diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe')
25 files changed, 7352 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/.gitignore b/arch/arm64/kvm/hyp/nvhe/.gitignore new file mode 100644 index 000000000000..5b6c43cc96f8 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +gen-hyprel +hyp.lds +hyp-reloc.S diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile new file mode 100644 index 000000000000..2250253a6429 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -0,0 +1,112 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for Kernel-based Virtual Machine module, HYP/nVHE part +# + +asflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS + +# Tracepoint and MMIO logging symbols should not be visible at nVHE KVM as +# there is no way to execute them and any such MMIO access from nVHE KVM +# will explode instantly (Words of Marc Zyngier). So introduce a generic flag +# __DISABLE_TRACE_MMIO__ to disable MMIO tracing for nVHE KVM. +ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS -D__DISABLE_TRACE_MMIO__ +ccflags-y += -fno-stack-protector \ + -DDISABLE_BRANCH_PROFILING \ + $(DISABLE_STACKLEAK_PLUGIN) + +hostprogs := gen-hyprel +HOST_EXTRACFLAGS += -I$(objtree)/include + +lib-objs := clear_page.o copy_page.o memcpy.o memset.o +lib-objs := $(addprefix ../../../lib/, $(lib-objs)) + +hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \ + hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \ + cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o +hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ + ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o +hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o +hyp-obj-y += $(lib-objs) + +## +## Build rules for compiling nVHE hyp code +## Output of this folder is `kvm_nvhe.o`, a partially linked object +## file containing all nVHE hyp code and data. +## + +hyp-obj := $(patsubst %.o,%.nvhe.o,$(hyp-obj-y)) +obj-y := kvm_nvhe.o +targets += $(hyp-obj) kvm_nvhe.tmp.o kvm_nvhe.rel.o hyp.lds hyp-reloc.S hyp-reloc.o + +# 1) Compile all source files to `.nvhe.o` object files. The file extension +# avoids file name clashes for files shared with VHE. +$(obj)/%.nvhe.o: $(src)/%.c FORCE + $(call if_changed_rule,cc_o_c) +$(obj)/%.nvhe.o: $(src)/%.S FORCE + $(call if_changed_rule,as_o_S) + +# 2) Compile linker script. +$(obj)/hyp.lds: $(src)/hyp.lds.S FORCE + $(call if_changed_dep,cpp_lds_S) + +# 3) Partially link all '.nvhe.o' files and apply the linker script. +# Prefixes names of ELF sections with '.hyp', eg. '.hyp.text'. +# Note: The following rule assumes that the 'ld' rule puts LDFLAGS before +# the list of dependencies to form '-T $(obj)/hyp.lds'. This is to +# keep the dependency on the target while avoiding an error from +# GNU ld if the linker script is passed to it twice. +LDFLAGS_kvm_nvhe.tmp.o := -r -T +$(obj)/kvm_nvhe.tmp.o: $(obj)/hyp.lds $(addprefix $(obj)/,$(hyp-obj)) FORCE + $(call if_changed,ld) + +# 4) Generate list of hyp code/data positions that need to be relocated at +# runtime. Because the hypervisor is part of the kernel binary, relocations +# produce a kernel VA. We enumerate relocations targeting hyp at build time +# and convert the kernel VAs at those positions to hyp VAs. +$(obj)/hyp-reloc.S: $(obj)/kvm_nvhe.tmp.o $(obj)/gen-hyprel FORCE + $(call if_changed,hyprel) + +# 5) Compile hyp-reloc.S and link it into the existing partially linked object. +# The object file now contains a section with pointers to hyp positions that +# will contain kernel VAs at runtime. These pointers have relocations on them +# so that they get updated as the hyp object is linked into `vmlinux`. +LDFLAGS_kvm_nvhe.rel.o := -r +$(obj)/kvm_nvhe.rel.o: $(obj)/kvm_nvhe.tmp.o $(obj)/hyp-reloc.o FORCE + $(call if_changed,ld) + +# 6) Produce the final 'kvm_nvhe.o', ready to be linked into 'vmlinux'. +# Prefixes names of ELF symbols with '__kvm_nvhe_'. +$(obj)/kvm_nvhe.o: $(obj)/kvm_nvhe.rel.o FORCE + $(call if_changed,hypcopy) + +# The HYPREL command calls `gen-hyprel` to generate an assembly file with +# a list of relocations targeting hyp code/data. +quiet_cmd_hyprel = HYPREL $@ + cmd_hyprel = $(obj)/gen-hyprel $< > $@ + +# The HYPCOPY command uses `objcopy` to prefix all ELF symbol names +# to avoid clashes with VHE code/data. +quiet_cmd_hypcopy = HYPCOPY $@ + cmd_hypcopy = $(OBJCOPY) --prefix-symbols=__kvm_nvhe_ $< $@ + +# Remove ftrace, Shadow Call Stack, and CFI CFLAGS. +# This is equivalent to the 'notrace', '__noscs', and '__nocfi' annotations. +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI), $(KBUILD_CFLAGS)) +# Starting from 13.0.0 llvm emits SHT_REL section '.llvm.call-graph-profile' +# when profile optimization is applied. gen-hyprel does not support SHT_REL and +# causes a build failure. Remove profile optimization flags. +KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%, $(KBUILD_CFLAGS)) +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables + +# KVM nVHE code is run at a different exception code with a different map, so +# compiler instrumentation that inserts callbacks or checks into the code may +# cause crashes. Just disable it. +GCOV_PROFILE := n +KASAN_SANITIZE := n +KCSAN_SANITIZE := n +UBSAN_SANITIZE := n +KCOV_INSTRUMENT := n + +# Skip objtool checking for this directory because nVHE code is compiled with +# non-standard build rules. +OBJECT_FILES_NON_STANDARD := y diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S new file mode 100644 index 000000000000..85936c17ae40 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/cache.S @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Code copied from arch/arm64/mm/cache.S. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/alternative.h> + +SYM_FUNC_START(__pi_dcache_clean_inval_poc) + dcache_by_line_op civac, sy, x0, x1, x2, x3 + ret +SYM_FUNC_END(__pi_dcache_clean_inval_poc) +SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc) + +SYM_FUNC_START(__pi_icache_inval_pou) +alternative_if ARM64_HAS_CACHE_DIC + isb + ret +alternative_else_nop_endif + + invalidate_icache_by_line x0, x1, x2, x3 + ret +SYM_FUNC_END(__pi_icache_inval_pou) +SYM_FUNC_ALIAS(icache_inval_pou, __pi_icache_inval_pou) diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c new file mode 100644 index 000000000000..7746ea507b6f --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/debug-sr.h> + +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/debug-monitors.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +static void __debug_save_spe(u64 *pmscr_el1) +{ + u64 reg; + + /* Clear pmscr in case of early return */ + *pmscr_el1 = 0; + + /* + * At this point, we know that this CPU implements + * SPE and is available to the host. + * Check if the host is actually using it ? + */ + reg = read_sysreg_s(SYS_PMBLIMITR_EL1); + if (!(reg & BIT(PMBLIMITR_EL1_E_SHIFT))) + return; + + /* Yes; save the control register and disable data generation */ + *pmscr_el1 = read_sysreg_el1(SYS_PMSCR); + write_sysreg_el1(0, SYS_PMSCR); + isb(); + + /* Now drain all buffered data to memory */ + psb_csync(); +} + +static void __debug_restore_spe(u64 pmscr_el1) +{ + if (!pmscr_el1) + return; + + /* The host page table is installed, but not yet synchronised */ + isb(); + + /* Re-enable data generation */ + write_sysreg_el1(pmscr_el1, SYS_PMSCR); +} + +static void __debug_save_trace(u64 *trfcr_el1) +{ + *trfcr_el1 = 0; + + /* Check if the TRBE is enabled */ + if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E)) + return; + /* + * Prohibit trace generation while we are in guest. + * Since access to TRFCR_EL1 is trapped, the guest can't + * modify the filtering set by the host. + */ + *trfcr_el1 = read_sysreg_el1(SYS_TRFCR); + write_sysreg_el1(0, SYS_TRFCR); + isb(); + /* Drain the trace buffer to memory */ + tsb_csync(); +} + +static void __debug_restore_trace(u64 trfcr_el1) +{ + if (!trfcr_el1) + return; + + /* Restore trace filter controls */ + write_sysreg_el1(trfcr_el1, SYS_TRFCR); +} + +void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) +{ + /* Disable and flush SPE data generation */ + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) + __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); + /* Disable and flush Self-Hosted Trace generation */ + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) + __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); +} + +void __debug_switch_to_guest(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_guest_common(vcpu); +} + +void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) +{ + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) + __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) + __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); +} + +void __debug_switch_to_host(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_host_common(vcpu); +} + +u64 __kvm_get_mdcr_el2(void) +{ + return read_sysreg(mdcr_el2); +} diff --git a/arch/arm64/kvm/hyp/nvhe/early_alloc.c b/arch/arm64/kvm/hyp/nvhe/early_alloc.c new file mode 100644 index 000000000000..00de04153cc6 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/early_alloc.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <asm/kvm_pgtable.h> + +#include <nvhe/early_alloc.h> +#include <nvhe/memory.h> + +struct kvm_pgtable_mm_ops hyp_early_alloc_mm_ops; +s64 __ro_after_init hyp_physvirt_offset; + +static unsigned long base; +static unsigned long end; +static unsigned long cur; + +unsigned long hyp_early_alloc_nr_used_pages(void) +{ + return (cur - base) >> PAGE_SHIFT; +} + +void *hyp_early_alloc_contig(unsigned int nr_pages) +{ + unsigned long size = (nr_pages << PAGE_SHIFT); + void *ret = (void *)cur; + + if (!nr_pages) + return NULL; + + if (end - cur < size) + return NULL; + + cur += size; + memset(ret, 0, size); + + return ret; +} + +void *hyp_early_alloc_page(void *arg) +{ + return hyp_early_alloc_contig(1); +} + +static void hyp_early_alloc_get_page(void *addr) { } +static void hyp_early_alloc_put_page(void *addr) { } + +void hyp_early_alloc_init(void *virt, unsigned long size) +{ + base = cur = (unsigned long)virt; + end = base + size; + + hyp_early_alloc_mm_ops.zalloc_page = hyp_early_alloc_page; + hyp_early_alloc_mm_ops.phys_to_virt = hyp_phys_to_virt; + hyp_early_alloc_mm_ops.virt_to_phys = hyp_virt_to_phys; + hyp_early_alloc_mm_ops.get_page = hyp_early_alloc_get_page; + hyp_early_alloc_mm_ops.put_page = hyp_early_alloc_put_page; +} diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c new file mode 100644 index 000000000000..320f2eaa14a9 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -0,0 +1,780 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * FF-A v1.0 proxy to filter out invalid memory-sharing SMC calls issued by + * the host. FF-A is a slightly more palatable abbreviation of "Arm Firmware + * Framework for Arm A-profile", which is specified by Arm in document + * number DEN0077. + * + * Copyright (C) 2022 - Google LLC + * Author: Andrew Walbran <qwandor@google.com> + * + * This driver hooks into the SMC trapping logic for the host and intercepts + * all calls falling within the FF-A range. Each call is either: + * + * - Forwarded on unmodified to the SPMD at EL3 + * - Rejected as "unsupported" + * - Accompanied by a host stage-2 page-table check/update and reissued + * + * Consequently, any attempts by the host to make guest memory pages + * accessible to the secure world using FF-A will be detected either here + * (in the case that the memory is already owned by the guest) or during + * donation to the guest (in the case that the memory was previously shared + * with the secure world). + * + * To allow the rolling-back of page-table updates and FF-A calls in the + * event of failure, operations involving the RXTX buffers are locked for + * the duration and are therefore serialised. + */ + +#include <linux/arm-smccc.h> +#include <linux/arm_ffa.h> +#include <asm/kvm_pkvm.h> + +#include <nvhe/ffa.h> +#include <nvhe/mem_protect.h> +#include <nvhe/memory.h> +#include <nvhe/trap_handler.h> +#include <nvhe/spinlock.h> + +/* + * "ID value 0 must be returned at the Non-secure physical FF-A instance" + * We share this ID with the host. + */ +#define HOST_FFA_ID 0 + +/* + * A buffer to hold the maximum descriptor size we can see from the host, + * which is required when the SPMD returns a fragmented FFA_MEM_RETRIEVE_RESP + * when resolving the handle on the reclaim path. + */ +struct kvm_ffa_descriptor_buffer { + void *buf; + size_t len; +}; + +static struct kvm_ffa_descriptor_buffer ffa_desc_buf; + +struct kvm_ffa_buffers { + hyp_spinlock_t lock; + void *tx; + void *rx; +}; + +/* + * Note that we don't currently lock these buffers explicitly, instead + * relying on the locking of the host FFA buffers as we only have one + * client. + */ +static struct kvm_ffa_buffers hyp_buffers; +static struct kvm_ffa_buffers host_buffers; + +static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno) +{ + *res = (struct arm_smccc_res) { + .a0 = FFA_ERROR, + .a2 = ffa_errno, + }; +} + +static void ffa_to_smccc_res_prop(struct arm_smccc_res *res, int ret, u64 prop) +{ + if (ret == FFA_RET_SUCCESS) { + *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS, + .a2 = prop }; + } else { + ffa_to_smccc_error(res, ret); + } +} + +static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret) +{ + ffa_to_smccc_res_prop(res, ret, 0); +} + +static void ffa_set_retval(struct kvm_cpu_context *ctxt, + struct arm_smccc_res *res) +{ + cpu_reg(ctxt, 0) = res->a0; + cpu_reg(ctxt, 1) = res->a1; + cpu_reg(ctxt, 2) = res->a2; + cpu_reg(ctxt, 3) = res->a3; +} + +static bool is_ffa_call(u64 func_id) +{ + return ARM_SMCCC_IS_FAST_CALL(func_id) && + ARM_SMCCC_OWNER_NUM(func_id) == ARM_SMCCC_OWNER_STANDARD && + ARM_SMCCC_FUNC_NUM(func_id) >= FFA_MIN_FUNC_NUM && + ARM_SMCCC_FUNC_NUM(func_id) <= FFA_MAX_FUNC_NUM; +} + +static int ffa_map_hyp_buffers(u64 ffa_page_count) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP, + hyp_virt_to_phys(hyp_buffers.tx), + hyp_virt_to_phys(hyp_buffers.rx), + ffa_page_count, + 0, 0, 0, 0, + &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static int ffa_unmap_hyp_buffers(void) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(FFA_RXTX_UNMAP, + HOST_FFA_ID, + 0, 0, 0, 0, 0, 0, + &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static void ffa_mem_frag_tx(struct arm_smccc_res *res, u32 handle_lo, + u32 handle_hi, u32 fraglen, u32 endpoint_id) +{ + arm_smccc_1_1_smc(FFA_MEM_FRAG_TX, + handle_lo, handle_hi, fraglen, endpoint_id, + 0, 0, 0, + res); +} + +static void ffa_mem_frag_rx(struct arm_smccc_res *res, u32 handle_lo, + u32 handle_hi, u32 fragoff) +{ + arm_smccc_1_1_smc(FFA_MEM_FRAG_RX, + handle_lo, handle_hi, fragoff, HOST_FFA_ID, + 0, 0, 0, + res); +} + +static void ffa_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len, + u32 fraglen) +{ + arm_smccc_1_1_smc(func_id, len, fraglen, + 0, 0, 0, 0, 0, + res); +} + +static void ffa_mem_reclaim(struct arm_smccc_res *res, u32 handle_lo, + u32 handle_hi, u32 flags) +{ + arm_smccc_1_1_smc(FFA_MEM_RECLAIM, + handle_lo, handle_hi, flags, + 0, 0, 0, 0, + res); +} + +static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len) +{ + arm_smccc_1_1_smc(FFA_FN64_MEM_RETRIEVE_REQ, + len, len, + 0, 0, 0, 0, 0, + res); +} + +static void do_ffa_rxtx_map(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(phys_addr_t, tx, ctxt, 1); + DECLARE_REG(phys_addr_t, rx, ctxt, 2); + DECLARE_REG(u32, npages, ctxt, 3); + int ret = 0; + void *rx_virt, *tx_virt; + + if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (!PAGE_ALIGNED(tx) || !PAGE_ALIGNED(rx)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (host_buffers.tx) { + ret = FFA_RET_DENIED; + goto out_unlock; + } + + /* + * Map our hypervisor buffers into the SPMD before mapping and + * pinning the host buffers in our own address space. + */ + ret = ffa_map_hyp_buffers(npages); + if (ret) + goto out_unlock; + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(tx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unmap; + } + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(rx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_tx; + } + + tx_virt = hyp_phys_to_virt(tx); + ret = hyp_pin_shared_mem(tx_virt, tx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_rx; + } + + rx_virt = hyp_phys_to_virt(rx); + ret = hyp_pin_shared_mem(rx_virt, rx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unpin_tx; + } + + host_buffers.tx = tx_virt; + host_buffers.rx = rx_virt; + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); + return; + +err_unpin_tx: + hyp_unpin_shared_mem(tx_virt, tx_virt + 1); +err_unshare_rx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(rx)); +err_unshare_tx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(tx)); +err_unmap: + ffa_unmap_hyp_buffers(); + goto out_unlock; +} + +static void do_ffa_rxtx_unmap(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, id, ctxt, 1); + int ret = 0; + + if (id != HOST_FFA_ID) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + hyp_unpin_shared_mem(host_buffers.tx, host_buffers.tx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.tx))); + host_buffers.tx = NULL; + + hyp_unpin_shared_mem(host_buffers.rx, host_buffers.rx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.rx))); + host_buffers.rx = NULL; + + ffa_unmap_hyp_buffers(); + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); +} + +static u32 __ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_share_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static u32 __ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_unshare_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static int ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nshared = __ffa_host_share_ranges(ranges, nranges); + int ret = 0; + + if (nshared != nranges) { + WARN_ON(__ffa_host_unshare_ranges(ranges, nshared) != nshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nunshared = __ffa_host_unshare_ranges(ranges, nranges); + int ret = 0; + + if (nunshared != nranges) { + WARN_ON(__ffa_host_share_ranges(ranges, nunshared) != nunshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, handle_lo, ctxt, 1); + DECLARE_REG(u32, handle_hi, ctxt, 2); + DECLARE_REG(u32, fraglen, ctxt, 3); + DECLARE_REG(u32, endpoint_id, ctxt, 4); + struct ffa_mem_region_addr_range *buf; + int ret = FFA_RET_INVALID_PARAMETERS; + u32 nr_ranges; + + if (fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) + goto out; + + if (fraglen % sizeof(*buf)) + goto out; + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) + goto out_unlock; + + buf = hyp_buffers.tx; + memcpy(buf, host_buffers.tx, fraglen); + nr_ranges = fraglen / sizeof(*buf); + + ret = ffa_host_share_ranges(buf, nr_ranges); + if (ret) { + /* + * We're effectively aborting the transaction, so we need + * to restore the global state back to what it was prior to + * transmission of the first fragment. + */ + ffa_mem_reclaim(res, handle_lo, handle_hi, 0); + WARN_ON(res->a0 != FFA_SUCCESS); + goto out_unlock; + } + + ffa_mem_frag_tx(res, handle_lo, handle_hi, fraglen, endpoint_id); + if (res->a0 != FFA_SUCCESS && res->a0 != FFA_MEM_FRAG_RX) + WARN_ON(ffa_host_unshare_ranges(buf, nr_ranges)); + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + if (ret) + ffa_to_smccc_res(res, ret); + + /* + * If for any reason this did not succeed, we're in trouble as we have + * now lost the content of the previous fragments and we can't rollback + * the host stage-2 changes. The pages previously marked as shared will + * remain stuck in that state forever, hence preventing the host from + * sharing/donating them again and may possibly lead to subsequent + * failures, but this will not compromise confidentiality. + */ + return; +} + +static __always_inline void do_ffa_mem_xfer(const u64 func_id, + struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, len, ctxt, 1); + DECLARE_REG(u32, fraglen, ctxt, 2); + DECLARE_REG(u64, addr_mbz, ctxt, 3); + DECLARE_REG(u32, npages_mbz, ctxt, 4); + struct ffa_mem_region_attributes *ep_mem_access; + struct ffa_composite_mem_region *reg; + struct ffa_mem_region *buf; + u32 offset, nr_ranges; + int ret = 0; + + BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE && + func_id != FFA_FN64_MEM_LEND); + + if (addr_mbz || npages_mbz || fraglen > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (fraglen < sizeof(struct ffa_mem_region) + + sizeof(struct ffa_mem_region_attributes)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + buf = hyp_buffers.tx; + memcpy(buf, host_buffers.tx, fraglen); + + ep_mem_access = (void *)buf + + ffa_mem_desc_offset(buf, 0, FFA_VERSION_1_0); + offset = ep_mem_access->composite_off; + if (!offset || buf->ep_count != 1 || buf->sender_id != HOST_FFA_ID) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + reg = (void *)buf + offset; + nr_ranges = ((void *)buf + fraglen) - (void *)reg->constituents; + if (nr_ranges % sizeof(reg->constituents[0])) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + nr_ranges /= sizeof(reg->constituents[0]); + ret = ffa_host_share_ranges(reg->constituents, nr_ranges); + if (ret) + goto out_unlock; + + ffa_mem_xfer(res, func_id, len, fraglen); + if (fraglen != len) { + if (res->a0 != FFA_MEM_FRAG_RX) + goto err_unshare; + + if (res->a3 != fraglen) + goto err_unshare; + } else if (res->a0 != FFA_SUCCESS) { + goto err_unshare; + } + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + if (ret) + ffa_to_smccc_res(res, ret); + return; + +err_unshare: + WARN_ON(ffa_host_unshare_ranges(reg->constituents, nr_ranges)); + goto out_unlock; +} + +static void do_ffa_mem_reclaim(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, handle_lo, ctxt, 1); + DECLARE_REG(u32, handle_hi, ctxt, 2); + DECLARE_REG(u32, flags, ctxt, 3); + struct ffa_mem_region_attributes *ep_mem_access; + struct ffa_composite_mem_region *reg; + u32 offset, len, fraglen, fragoff; + struct ffa_mem_region *buf; + int ret = 0; + u64 handle; + + handle = PACK_HANDLE(handle_lo, handle_hi); + + hyp_spin_lock(&host_buffers.lock); + + buf = hyp_buffers.tx; + *buf = (struct ffa_mem_region) { + .sender_id = HOST_FFA_ID, + .handle = handle, + }; + + ffa_retrieve_req(res, sizeof(*buf)); + buf = hyp_buffers.rx; + if (res->a0 != FFA_MEM_RETRIEVE_RESP) + goto out_unlock; + + len = res->a1; + fraglen = res->a2; + + ep_mem_access = (void *)buf + + ffa_mem_desc_offset(buf, 0, FFA_VERSION_1_0); + offset = ep_mem_access->composite_off; + /* + * We can trust the SPMD to get this right, but let's at least + * check that we end up with something that doesn't look _completely_ + * bogus. + */ + if (WARN_ON(offset > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) { + ret = FFA_RET_ABORTED; + goto out_unlock; + } + + if (len > ffa_desc_buf.len) { + ret = FFA_RET_NO_MEMORY; + goto out_unlock; + } + + buf = ffa_desc_buf.buf; + memcpy(buf, hyp_buffers.rx, fraglen); + + for (fragoff = fraglen; fragoff < len; fragoff += fraglen) { + ffa_mem_frag_rx(res, handle_lo, handle_hi, fragoff); + if (res->a0 != FFA_MEM_FRAG_TX) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + fraglen = res->a3; + memcpy((void *)buf + fragoff, hyp_buffers.rx, fraglen); + } + + ffa_mem_reclaim(res, handle_lo, handle_hi, flags); + if (res->a0 != FFA_SUCCESS) + goto out_unlock; + + reg = (void *)buf + offset; + /* If the SPMD was happy, then we should be too. */ + WARN_ON(ffa_host_unshare_ranges(reg->constituents, + reg->addr_range_cnt)); +out_unlock: + hyp_spin_unlock(&host_buffers.lock); + + if (ret) + ffa_to_smccc_res(res, ret); +} + +/* + * Is a given FFA function supported, either by forwarding on directly + * or by handling at EL2? + */ +static bool ffa_call_supported(u64 func_id) +{ + switch (func_id) { + /* Unsupported memory management calls */ + case FFA_FN64_MEM_RETRIEVE_REQ: + case FFA_MEM_RETRIEVE_RESP: + case FFA_MEM_RELINQUISH: + case FFA_MEM_OP_PAUSE: + case FFA_MEM_OP_RESUME: + case FFA_MEM_FRAG_RX: + case FFA_FN64_MEM_DONATE: + /* Indirect message passing via RX/TX buffers */ + case FFA_MSG_SEND: + case FFA_MSG_POLL: + case FFA_MSG_WAIT: + /* 32-bit variants of 64-bit calls */ + case FFA_MSG_SEND_DIRECT_REQ: + case FFA_MSG_SEND_DIRECT_RESP: + case FFA_RXTX_MAP: + case FFA_MEM_DONATE: + case FFA_MEM_RETRIEVE_REQ: + return false; + } + + return true; +} + +static bool do_ffa_features(struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, id, ctxt, 1); + u64 prop = 0; + int ret = 0; + + if (!ffa_call_supported(id)) { + ret = FFA_RET_NOT_SUPPORTED; + goto out_handled; + } + + switch (id) { + case FFA_MEM_SHARE: + case FFA_FN64_MEM_SHARE: + case FFA_MEM_LEND: + case FFA_FN64_MEM_LEND: + ret = FFA_RET_SUCCESS; + prop = 0; /* No support for dynamic buffers */ + goto out_handled; + default: + return false; + } + +out_handled: + ffa_to_smccc_res_prop(res, ret, prop); + return true; +} + +bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id) +{ + struct arm_smccc_res res; + + /* + * There's no way we can tell what a non-standard SMC call might + * be up to. Ideally, we would terminate these here and return + * an error to the host, but sadly devices make use of custom + * firmware calls for things like power management, debugging, + * RNG access and crash reporting. + * + * Given that the architecture requires us to trust EL3 anyway, + * we forward unrecognised calls on under the assumption that + * the firmware doesn't expose a mechanism to access arbitrary + * non-secure memory. Short of a per-device table of SMCs, this + * is the best we can do. + */ + if (!is_ffa_call(func_id)) + return false; + + switch (func_id) { + case FFA_FEATURES: + if (!do_ffa_features(&res, host_ctxt)) + return false; + goto out_handled; + /* Memory management */ + case FFA_FN64_RXTX_MAP: + do_ffa_rxtx_map(&res, host_ctxt); + goto out_handled; + case FFA_RXTX_UNMAP: + do_ffa_rxtx_unmap(&res, host_ctxt); + goto out_handled; + case FFA_MEM_SHARE: + case FFA_FN64_MEM_SHARE: + do_ffa_mem_xfer(FFA_FN64_MEM_SHARE, &res, host_ctxt); + goto out_handled; + case FFA_MEM_RECLAIM: + do_ffa_mem_reclaim(&res, host_ctxt); + goto out_handled; + case FFA_MEM_LEND: + case FFA_FN64_MEM_LEND: + do_ffa_mem_xfer(FFA_FN64_MEM_LEND, &res, host_ctxt); + goto out_handled; + case FFA_MEM_FRAG_TX: + do_ffa_mem_frag_tx(&res, host_ctxt); + goto out_handled; + } + + if (ffa_call_supported(func_id)) + return false; /* Pass through */ + + ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED); +out_handled: + ffa_set_retval(host_ctxt, &res); + return true; +} + +int hyp_ffa_init(void *pages) +{ + struct arm_smccc_res res; + size_t min_rxtx_sz; + void *tx, *rx; + + if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2) + return 0; + + arm_smccc_1_1_smc(FFA_VERSION, FFA_VERSION_1_0, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 == FFA_RET_NOT_SUPPORTED) + return 0; + + /* + * Firmware returns the maximum supported version of the FF-A + * implementation. Check that the returned version is + * backwards-compatible with the hyp according to the rules in DEN0077A + * v1.1 REL0 13.2.1. + * + * Of course, things are never simple when dealing with firmware. v1.1 + * broke ABI with v1.0 on several structures, which is itself + * incompatible with the aforementioned versioning scheme. The + * expectation is that v1.x implementations that do not support the v1.0 + * ABI return NOT_SUPPORTED rather than a version number, according to + * DEN0077A v1.1 REL0 18.6.4. + */ + if (FFA_MAJOR_VERSION(res.a0) != 1) + return -EOPNOTSUPP; + + arm_smccc_1_1_smc(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 != FFA_SUCCESS) + return -EOPNOTSUPP; + + if (res.a2 != HOST_FFA_ID) + return -EINVAL; + + arm_smccc_1_1_smc(FFA_FEATURES, FFA_FN64_RXTX_MAP, + 0, 0, 0, 0, 0, 0, &res); + if (res.a0 != FFA_SUCCESS) + return -EOPNOTSUPP; + + switch (res.a2) { + case FFA_FEAT_RXTX_MIN_SZ_4K: + min_rxtx_sz = SZ_4K; + break; + case FFA_FEAT_RXTX_MIN_SZ_16K: + min_rxtx_sz = SZ_16K; + break; + case FFA_FEAT_RXTX_MIN_SZ_64K: + min_rxtx_sz = SZ_64K; + break; + default: + return -EINVAL; + } + + if (min_rxtx_sz > PAGE_SIZE) + return -EOPNOTSUPP; + + tx = pages; + pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE; + rx = pages; + pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE; + + ffa_desc_buf = (struct kvm_ffa_descriptor_buffer) { + .buf = pages, + .len = PAGE_SIZE * + (hyp_ffa_proxy_pages() - (2 * KVM_FFA_MBOX_NR_PAGES)), + }; + + hyp_buffers = (struct kvm_ffa_buffers) { + .lock = __HYP_SPIN_LOCK_UNLOCKED, + .tx = tx, + .rx = rx, + }; + + host_buffers = (struct kvm_ffa_buffers) { + .lock = __HYP_SPIN_LOCK_UNLOCKED, + }; + + return 0; +} diff --git a/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c b/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c new file mode 100644 index 000000000000..6bc88a756cb7 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 - Google LLC + * Author: David Brazdil <dbrazdil@google.com> + * + * Generates relocation information used by the kernel to convert + * absolute addresses in hyp data from kernel VAs to hyp VAs. + * + * This is necessary because hyp code is linked into the same binary + * as the kernel but executes under different memory mappings. + * If the compiler used absolute addressing, those addresses need to + * be converted before they are used by hyp code. + * + * The input of this program is the relocatable ELF object containing + * all hyp code/data, not yet linked into vmlinux. Hyp section names + * should have been prefixed with `.hyp` at this point. + * + * The output (printed to stdout) is an assembly file containing + * an array of 32-bit integers and static relocations that instruct + * the linker of `vmlinux` to populate the array entries with offsets + * to positions in the kernel binary containing VAs used by hyp code. + * + * Note that dynamic relocations could be used for the same purpose. + * However, those are only generated if CONFIG_RELOCATABLE=y. + */ + +#include <elf.h> +#include <endian.h> +#include <errno.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> + +#include <generated/autoconf.h> + +#define HYP_SECTION_PREFIX ".hyp" +#define HYP_RELOC_SECTION ".hyp.reloc" +#define HYP_SECTION_SYMBOL_PREFIX "__hyp_section_" + +/* + * AArch64 relocation type constants. + * Included in case these are not defined in the host toolchain. + */ +#ifndef R_AARCH64_ABS64 +#define R_AARCH64_ABS64 257 +#endif +#ifndef R_AARCH64_PREL64 +#define R_AARCH64_PREL64 260 +#endif +#ifndef R_AARCH64_PREL32 +#define R_AARCH64_PREL32 261 +#endif +#ifndef R_AARCH64_PREL16 +#define R_AARCH64_PREL16 262 +#endif +#ifndef R_AARCH64_PLT32 +#define R_AARCH64_PLT32 314 +#endif +#ifndef R_AARCH64_LD_PREL_LO19 +#define R_AARCH64_LD_PREL_LO19 273 +#endif +#ifndef R_AARCH64_ADR_PREL_LO21 +#define R_AARCH64_ADR_PREL_LO21 274 +#endif +#ifndef R_AARCH64_ADR_PREL_PG_HI21 +#define R_AARCH64_ADR_PREL_PG_HI21 275 +#endif +#ifndef R_AARCH64_ADR_PREL_PG_HI21_NC +#define R_AARCH64_ADR_PREL_PG_HI21_NC 276 +#endif +#ifndef R_AARCH64_ADD_ABS_LO12_NC +#define R_AARCH64_ADD_ABS_LO12_NC 277 +#endif +#ifndef R_AARCH64_LDST8_ABS_LO12_NC +#define R_AARCH64_LDST8_ABS_LO12_NC 278 +#endif +#ifndef R_AARCH64_TSTBR14 +#define R_AARCH64_TSTBR14 279 +#endif +#ifndef R_AARCH64_CONDBR19 +#define R_AARCH64_CONDBR19 280 +#endif +#ifndef R_AARCH64_JUMP26 +#define R_AARCH64_JUMP26 282 +#endif +#ifndef R_AARCH64_CALL26 +#define R_AARCH64_CALL26 283 +#endif +#ifndef R_AARCH64_LDST16_ABS_LO12_NC +#define R_AARCH64_LDST16_ABS_LO12_NC 284 +#endif +#ifndef R_AARCH64_LDST32_ABS_LO12_NC +#define R_AARCH64_LDST32_ABS_LO12_NC 285 +#endif +#ifndef R_AARCH64_LDST64_ABS_LO12_NC +#define R_AARCH64_LDST64_ABS_LO12_NC 286 +#endif +#ifndef R_AARCH64_MOVW_PREL_G0 +#define R_AARCH64_MOVW_PREL_G0 287 +#endif +#ifndef R_AARCH64_MOVW_PREL_G0_NC +#define R_AARCH64_MOVW_PREL_G0_NC 288 +#endif +#ifndef R_AARCH64_MOVW_PREL_G1 +#define R_AARCH64_MOVW_PREL_G1 289 +#endif +#ifndef R_AARCH64_MOVW_PREL_G1_NC +#define R_AARCH64_MOVW_PREL_G1_NC 290 +#endif +#ifndef R_AARCH64_MOVW_PREL_G2 +#define R_AARCH64_MOVW_PREL_G2 291 +#endif +#ifndef R_AARCH64_MOVW_PREL_G2_NC +#define R_AARCH64_MOVW_PREL_G2_NC 292 +#endif +#ifndef R_AARCH64_MOVW_PREL_G3 +#define R_AARCH64_MOVW_PREL_G3 293 +#endif +#ifndef R_AARCH64_LDST128_ABS_LO12_NC +#define R_AARCH64_LDST128_ABS_LO12_NC 299 +#endif + +/* Global state of the processed ELF. */ +static struct { + const char *path; + char *begin; + size_t size; + Elf64_Ehdr *ehdr; + Elf64_Shdr *sh_table; + const char *sh_string; +} elf; + +#if defined(CONFIG_CPU_LITTLE_ENDIAN) + +#define elf16toh(x) le16toh(x) +#define elf32toh(x) le32toh(x) +#define elf64toh(x) le64toh(x) + +#define ELFENDIAN ELFDATA2LSB + +#elif defined(CONFIG_CPU_BIG_ENDIAN) + +#define elf16toh(x) be16toh(x) +#define elf32toh(x) be32toh(x) +#define elf64toh(x) be64toh(x) + +#define ELFENDIAN ELFDATA2MSB + +#else + +#error PDP-endian sadly unsupported... + +#endif + +#define fatal_error(fmt, ...) \ + ({ \ + fprintf(stderr, "error: %s: " fmt "\n", \ + elf.path, ## __VA_ARGS__); \ + exit(EXIT_FAILURE); \ + __builtin_unreachable(); \ + }) + +#define fatal_perror(msg) \ + ({ \ + fprintf(stderr, "error: %s: " msg ": %s\n", \ + elf.path, strerror(errno)); \ + exit(EXIT_FAILURE); \ + __builtin_unreachable(); \ + }) + +#define assert_op(lhs, rhs, fmt, op) \ + ({ \ + typeof(lhs) _lhs = (lhs); \ + typeof(rhs) _rhs = (rhs); \ + \ + if (!(_lhs op _rhs)) { \ + fatal_error("assertion " #lhs " " #op " " #rhs \ + " failed (lhs=" fmt ", rhs=" fmt \ + ", line=%d)", _lhs, _rhs, __LINE__); \ + } \ + }) + +#define assert_eq(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, ==) +#define assert_ne(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, !=) +#define assert_lt(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, <) +#define assert_ge(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, >=) + +/* + * Return a pointer of a given type at a given offset from + * the beginning of the ELF file. + */ +#define elf_ptr(type, off) ((type *)(elf.begin + (off))) + +/* Iterate over all sections in the ELF. */ +#define for_each_section(var) \ + for (var = elf.sh_table; var < elf.sh_table + elf16toh(elf.ehdr->e_shnum); ++var) + +/* Iterate over all Elf64_Rela relocations in a given section. */ +#define for_each_rela(shdr, var) \ + for (var = elf_ptr(Elf64_Rela, elf64toh(shdr->sh_offset)); \ + var < elf_ptr(Elf64_Rela, elf64toh(shdr->sh_offset) + elf64toh(shdr->sh_size)); var++) + +/* True if a string starts with a given prefix. */ +static inline bool starts_with(const char *str, const char *prefix) +{ + return memcmp(str, prefix, strlen(prefix)) == 0; +} + +/* Returns a string containing the name of a given section. */ +static inline const char *section_name(Elf64_Shdr *shdr) +{ + return elf.sh_string + elf32toh(shdr->sh_name); +} + +/* Returns a pointer to the first byte of section data. */ +static inline const char *section_begin(Elf64_Shdr *shdr) +{ + return elf_ptr(char, elf64toh(shdr->sh_offset)); +} + +/* Find a section by its offset from the beginning of the file. */ +static inline Elf64_Shdr *section_by_off(Elf64_Off off) +{ + assert_ne(off, 0UL, "%lu"); + return elf_ptr(Elf64_Shdr, off); +} + +/* Find a section by its index. */ +static inline Elf64_Shdr *section_by_idx(uint16_t idx) +{ + assert_ne(idx, SHN_UNDEF, "%u"); + return &elf.sh_table[idx]; +} + +/* + * Memory-map the given ELF file, perform sanity checks, and + * populate global state. + */ +static void init_elf(const char *path) +{ + int fd, ret; + struct stat stat; + + /* Store path in the global struct for error printing. */ + elf.path = path; + + /* Open the ELF file. */ + fd = open(path, O_RDONLY); + if (fd < 0) + fatal_perror("Could not open ELF file"); + + /* Get status of ELF file to obtain its size. */ + ret = fstat(fd, &stat); + if (ret < 0) { + close(fd); + fatal_perror("Could not get status of ELF file"); + } + + /* mmap() the entire ELF file read-only at an arbitrary address. */ + elf.begin = mmap(0, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + if (elf.begin == MAP_FAILED) { + close(fd); + fatal_perror("Could not mmap ELF file"); + } + + /* mmap() was successful, close the FD. */ + close(fd); + + /* Get pointer to the ELF header. */ + assert_ge(stat.st_size, sizeof(*elf.ehdr), "%lu"); + elf.ehdr = elf_ptr(Elf64_Ehdr, 0); + + /* Check the ELF magic. */ + assert_eq(elf.ehdr->e_ident[EI_MAG0], ELFMAG0, "0x%x"); + assert_eq(elf.ehdr->e_ident[EI_MAG1], ELFMAG1, "0x%x"); + assert_eq(elf.ehdr->e_ident[EI_MAG2], ELFMAG2, "0x%x"); + assert_eq(elf.ehdr->e_ident[EI_MAG3], ELFMAG3, "0x%x"); + + /* Sanity check that this is an ELF64 relocatable object for AArch64. */ + assert_eq(elf.ehdr->e_ident[EI_CLASS], ELFCLASS64, "%u"); + assert_eq(elf.ehdr->e_ident[EI_DATA], ELFENDIAN, "%u"); + assert_eq(elf16toh(elf.ehdr->e_type), ET_REL, "%u"); + assert_eq(elf16toh(elf.ehdr->e_machine), EM_AARCH64, "%u"); + + /* Populate fields of the global struct. */ + elf.sh_table = section_by_off(elf64toh(elf.ehdr->e_shoff)); + elf.sh_string = section_begin(section_by_idx(elf16toh(elf.ehdr->e_shstrndx))); +} + +/* Print the prologue of the output ASM file. */ +static void emit_prologue(void) +{ + printf(".data\n" + ".pushsection " HYP_RELOC_SECTION ", \"a\"\n"); +} + +/* Print ASM statements needed as a prologue to a processed hyp section. */ +static void emit_section_prologue(const char *sh_orig_name) +{ + /* Declare the hyp section symbol. */ + printf(".global %s%s\n", HYP_SECTION_SYMBOL_PREFIX, sh_orig_name); +} + +/* + * Print ASM statements to create a hyp relocation entry for a given + * R_AARCH64_ABS64 relocation. + * + * The linker of vmlinux will populate the position given by `rela` with + * an absolute 64-bit kernel VA. If the kernel is relocatable, it will + * also generate a dynamic relocation entry so that the kernel can shift + * the address at runtime for KASLR. + * + * Emit a 32-bit offset from the current address to the position given + * by `rela`. This way the kernel can iterate over all kernel VAs used + * by hyp at runtime and convert them to hyp VAs. However, that offset + * will not be known until linking of `vmlinux`, so emit a PREL32 + * relocation referencing a symbol that the hyp linker script put at + * the beginning of the relocated section + the offset from `rela`. + */ +static void emit_rela_abs64(Elf64_Rela *rela, const char *sh_orig_name) +{ + /* Offset of this reloc from the beginning of HYP_RELOC_SECTION. */ + static size_t reloc_offset; + + /* Create storage for the 32-bit offset. */ + printf(".word 0\n"); + + /* + * Create a PREL32 relocation which instructs the linker of `vmlinux` + * to insert offset to position <base> + <offset>, where <base> is + * a symbol at the beginning of the relocated section, and <offset> + * is `rela->r_offset`. + */ + printf(".reloc %lu, R_AARCH64_PREL32, %s%s + 0x%lx\n", + reloc_offset, HYP_SECTION_SYMBOL_PREFIX, sh_orig_name, + elf64toh(rela->r_offset)); + + reloc_offset += 4; +} + +/* Print the epilogue of the output ASM file. */ +static void emit_epilogue(void) +{ + printf(".popsection\n"); +} + +/* + * Iterate over all RELA relocations in a given section and emit + * hyp relocation data for all absolute addresses in hyp code/data. + * + * Static relocations that generate PC-relative-addressing are ignored. + * Failure is reported for unexpected relocation types. + */ +static void emit_rela_section(Elf64_Shdr *sh_rela) +{ + Elf64_Shdr *sh_orig = &elf.sh_table[elf32toh(sh_rela->sh_info)]; + const char *sh_orig_name = section_name(sh_orig); + Elf64_Rela *rela; + + /* Skip all non-hyp sections. */ + if (!starts_with(sh_orig_name, HYP_SECTION_PREFIX)) + return; + + emit_section_prologue(sh_orig_name); + + for_each_rela(sh_rela, rela) { + uint32_t type = (uint32_t)elf64toh(rela->r_info); + + /* Check that rela points inside the relocated section. */ + assert_lt(elf64toh(rela->r_offset), elf64toh(sh_orig->sh_size), "0x%lx"); + + switch (type) { + /* + * Data relocations to generate absolute addressing. + * Emit a hyp relocation. + */ + case R_AARCH64_ABS64: + emit_rela_abs64(rela, sh_orig_name); + break; + /* Allow position-relative data relocations. */ + case R_AARCH64_PREL64: + case R_AARCH64_PREL32: + case R_AARCH64_PREL16: + case R_AARCH64_PLT32: + break; + /* Allow relocations to generate PC-relative addressing. */ + case R_AARCH64_LD_PREL_LO19: + case R_AARCH64_ADR_PREL_LO21: + case R_AARCH64_ADR_PREL_PG_HI21: + case R_AARCH64_ADR_PREL_PG_HI21_NC: + case R_AARCH64_ADD_ABS_LO12_NC: + case R_AARCH64_LDST8_ABS_LO12_NC: + case R_AARCH64_LDST16_ABS_LO12_NC: + case R_AARCH64_LDST32_ABS_LO12_NC: + case R_AARCH64_LDST64_ABS_LO12_NC: + case R_AARCH64_LDST128_ABS_LO12_NC: + break; + /* Allow relative relocations for control-flow instructions. */ + case R_AARCH64_TSTBR14: + case R_AARCH64_CONDBR19: + case R_AARCH64_JUMP26: + case R_AARCH64_CALL26: + break; + /* Allow group relocations to create PC-relative offset inline. */ + case R_AARCH64_MOVW_PREL_G0: + case R_AARCH64_MOVW_PREL_G0_NC: + case R_AARCH64_MOVW_PREL_G1: + case R_AARCH64_MOVW_PREL_G1_NC: + case R_AARCH64_MOVW_PREL_G2: + case R_AARCH64_MOVW_PREL_G2_NC: + case R_AARCH64_MOVW_PREL_G3: + break; + default: + fatal_error("Unexpected RELA type %u", type); + } + } +} + +/* Iterate over all sections and emit hyp relocation data for RELA sections. */ +static void emit_all_relocs(void) +{ + Elf64_Shdr *shdr; + + for_each_section(shdr) { + switch (elf32toh(shdr->sh_type)) { + case SHT_REL: + fatal_error("Unexpected SHT_REL section \"%s\"", + section_name(shdr)); + case SHT_RELA: + emit_rela_section(shdr); + break; + } + } +} + +int main(int argc, const char **argv) +{ + if (argc != 2) { + fprintf(stderr, "Usage: %s <elf_input>\n", argv[0]); + return EXIT_FAILURE; + } + + init_elf(argv[1]); + + emit_prologue(); + emit_all_relocs(); + emit_epilogue(); + + return EXIT_SUCCESS; +} diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S new file mode 100644 index 000000000000..135cfb294ee5 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -0,0 +1,309 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 - Google Inc + * Author: Andrew Scull <ascull@google.com> + */ + +#include <linux/linkage.h> + +#include <asm/assembler.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_ptrauth.h> + + .text + +SYM_FUNC_START(__host_exit) + get_host_ctxt x0, x1 + + /* Store the host regs x2 and x3 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] + + /* Retrieve the host regs x0-x1 from the stack */ + ldp x2, x3, [sp], #16 // x0, x1 + + /* Store the host regs x0-x1 and x4-x17 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] + stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] + + /* Store the host regs x18-x29, lr */ + save_callee_saved_regs x0 + + /* Save the host context pointer in x29 across the function call */ + mov x29, x0 + +#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL +alternative_if_not ARM64_HAS_ADDRESS_AUTH +b __skip_pauth_save +alternative_else_nop_endif + +alternative_if ARM64_KVM_PROTECTED_MODE + /* Save kernel ptrauth keys. */ + add x18, x29, #CPU_APIAKEYLO_EL1 + ptrauth_save_state x18, x19, x20 + + /* Use hyp keys. */ + adr_this_cpu x18, kvm_hyp_ctxt, x19 + add x18, x18, #CPU_APIAKEYLO_EL1 + ptrauth_restore_state x18, x19, x20 + isb +alternative_else_nop_endif +__skip_pauth_save: +#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + + bl handle_trap + +__host_enter_restore_full: + /* Restore kernel keys. */ +#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL +alternative_if_not ARM64_HAS_ADDRESS_AUTH +b __skip_pauth_restore +alternative_else_nop_endif + +alternative_if ARM64_KVM_PROTECTED_MODE + add x18, x29, #CPU_APIAKEYLO_EL1 + ptrauth_restore_state x18, x19, x20 +alternative_else_nop_endif +__skip_pauth_restore: +#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + + /* Restore host regs x0-x17 */ + ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] + + /* x0-7 are use for panic arguments */ +__host_enter_for_panic: + ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] + + /* Restore host regs x18-x29, lr */ + restore_callee_saved_regs x29 + + /* Do not touch any register after this! */ +__host_enter_without_restoring: + eret + sb +SYM_FUNC_END(__host_exit) + +/* + * void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); + */ +SYM_FUNC_START(__host_enter) + mov x29, x0 + b __host_enter_restore_full +SYM_FUNC_END(__host_enter) + +/* + * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, + * u64 elr, u64 par); + */ +SYM_FUNC_START(__hyp_do_panic) + /* Prepare and exit to the host's panic function. */ + mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ + PSR_MODE_EL1h) + msr spsr_el2, lr + adr_l lr, nvhe_hyp_panic_handler + hyp_kimg_va lr, x6 + msr elr_el2, lr + + mov x29, x0 + +#ifdef CONFIG_NVHE_EL2_DEBUG + /* Ensure host stage-2 is disabled */ + mrs x0, hcr_el2 + bic x0, x0, #HCR_VM + msr hcr_el2, x0 + isb + tlbi vmalls12e1 + dsb nsh +#endif + + /* Load the panic arguments into x0-7 */ + mrs x0, esr_el2 + mov x4, x3 + mov x3, x2 + hyp_pa x3, x6 + get_vcpu_ptr x5, x6 + mrs x6, far_el2 + mrs x7, hpfar_el2 + + /* Enter the host, conditionally restoring the host context. */ + cbz x29, __host_enter_without_restoring + b __host_enter_for_panic +SYM_FUNC_END(__hyp_do_panic) + +SYM_FUNC_START(__host_hvc) + ldp x0, x1, [sp] // Don't fixup the stack yet + + /* No stub for you, sonny Jim */ +alternative_if ARM64_KVM_PROTECTED_MODE + b __host_exit +alternative_else_nop_endif + + /* Check for a stub HVC call */ + cmp x0, #HVC_STUB_HCALL_NR + b.hs __host_exit + + add sp, sp, #16 + /* + * Compute the idmap address of __kvm_handle_stub_hvc and + * jump there. + * + * Preserve x0-x4, which may contain stub parameters. + */ + adr_l x5, __kvm_handle_stub_hvc + hyp_pa x5, x6 + br x5 +SYM_FUNC_END(__host_hvc) + +.macro host_el1_sync_vect + .align 7 +.L__vect_start\@: + stp x0, x1, [sp, #-16]! + mrs x0, esr_el2 + ubfx x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH + cmp x0, #ESR_ELx_EC_HVC64 + b.eq __host_hvc + b __host_exit +.L__vect_end\@: +.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) + .error "host_el1_sync_vect larger than vector entry" +.endif +.endm + +.macro invalid_host_el2_vect + .align 7 + + /* + * Test whether the SP has overflowed, without corrupting a GPR. + * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit + * of SP should always be 1. + */ + add sp, sp, x0 // sp' = sp + x0 + sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp + tbz x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@ + sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 + sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp + + /* If a guest is loaded, panic out of it. */ + stp x0, x1, [sp, #-16]! + get_loaded_vcpu x0, x1 + cbnz x0, __guest_exit_panic + add sp, sp, #16 + + /* + * The panic may not be clean if the exception is taken before the host + * context has been saved by __host_exit or after the hyp context has + * been partially clobbered by __host_enter. + */ + b hyp_panic + +.L__hyp_sp_overflow\@: + /* Switch to the overflow stack */ + adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0 + + b hyp_panic_bad_stack + ASM_BUG() +.endm + +.macro invalid_host_el1_vect + .align 7 + mov x0, xzr /* restore_host = false */ + mrs x1, spsr_el2 + mrs x2, elr_el2 + mrs x3, par_el1 + b __hyp_do_panic +.endm + +/* + * The host vector does not use an ESB instruction in order to avoid consuming + * SErrors that should only be consumed by the host. Guest entry is deferred by + * __guest_enter if there are any pending asynchronous exceptions so hyp will + * always return to the host without having consumerd host SErrors. + * + * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the + * host knows about the EL2 vectors already, and there is no point in hiding + * them. + */ + .align 11 +SYM_CODE_START(__kvm_hyp_host_vector) + invalid_host_el2_vect // Synchronous EL2t + invalid_host_el2_vect // IRQ EL2t + invalid_host_el2_vect // FIQ EL2t + invalid_host_el2_vect // Error EL2t + + invalid_host_el2_vect // Synchronous EL2h + invalid_host_el2_vect // IRQ EL2h + invalid_host_el2_vect // FIQ EL2h + invalid_host_el2_vect // Error EL2h + + host_el1_sync_vect // Synchronous 64-bit EL1/EL0 + invalid_host_el1_vect // IRQ 64-bit EL1/EL0 + invalid_host_el1_vect // FIQ 64-bit EL1/EL0 + invalid_host_el1_vect // Error 64-bit EL1/EL0 + + host_el1_sync_vect // Synchronous 32-bit EL1/EL0 + invalid_host_el1_vect // IRQ 32-bit EL1/EL0 + invalid_host_el1_vect // FIQ 32-bit EL1/EL0 + invalid_host_el1_vect // Error 32-bit EL1/EL0 +SYM_CODE_END(__kvm_hyp_host_vector) + +/* + * Forward SMC with arguments in struct kvm_cpu_context, and + * store the result into the same struct. Assumes SMCCC 1.2 or older. + * + * x0: struct kvm_cpu_context* + */ +SYM_CODE_START(__kvm_hyp_host_forward_smc) + /* + * Use x18 to keep the pointer to the host context because + * x18 is callee-saved in SMCCC but not in AAPCS64. + */ + mov x18, x0 + + ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] + ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] + + smc #0 + + stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] + stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] + stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] + + ret +SYM_CODE_END(__kvm_hyp_host_forward_smc) + +/* + * kvm_host_psci_cpu_entry is called through br instruction, which requires + * bti j instruction as compilers (gcc and llvm) doesn't insert bti j for external + * functions, but bti c instead. + */ +SYM_CODE_START(kvm_host_psci_cpu_entry) + bti j + b __kvm_host_psci_cpu_entry +SYM_CODE_END(kvm_host_psci_cpu_entry) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S new file mode 100644 index 000000000000..2994878d68ea --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -0,0 +1,297 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <linux/arm-smccc.h> +#include <linux/linkage.h> + +#include <asm/alternative.h> +#include <asm/assembler.h> +#include <asm/el2_setup.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> +#include <asm/pgtable-hwdef.h> +#include <asm/sysreg.h> +#include <asm/virt.h> + + .text + .pushsection .idmap.text, "ax" + + .align 11 + +SYM_CODE_START(__kvm_hyp_init) + ventry __invalid // Synchronous EL2t + ventry __invalid // IRQ EL2t + ventry __invalid // FIQ EL2t + ventry __invalid // Error EL2t + + ventry __invalid // Synchronous EL2h + ventry __invalid // IRQ EL2h + ventry __invalid // FIQ EL2h + ventry __invalid // Error EL2h + + ventry __do_hyp_init // Synchronous 64-bit EL1 + ventry __invalid // IRQ 64-bit EL1 + ventry __invalid // FIQ 64-bit EL1 + ventry __invalid // Error 64-bit EL1 + + ventry __invalid // Synchronous 32-bit EL1 + ventry __invalid // IRQ 32-bit EL1 + ventry __invalid // FIQ 32-bit EL1 + ventry __invalid // Error 32-bit EL1 + +__invalid: + b . + + /* + * Only uses x0..x3 so as to not clobber callee-saved SMCCC registers. + * + * x0: SMCCC function ID + * x1: struct kvm_nvhe_init_params PA + */ +__do_hyp_init: + /* Check for a stub HVC call */ + cmp x0, #HVC_STUB_HCALL_NR + b.lo __kvm_handle_stub_hvc + + bic x0, x0, #ARM_SMCCC_CALL_HINTS + mov x3, #KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) + cmp x0, x3 + b.eq 1f + + mov x0, #SMCCC_RET_NOT_SUPPORTED + eret + +1: mov x0, x1 + mov x3, lr + bl ___kvm_hyp_init // Clobbers x0..x2 + mov lr, x3 + + /* Hello, World! */ + mov x0, #SMCCC_RET_SUCCESS + eret +SYM_CODE_END(__kvm_hyp_init) + +/* + * Initialize the hypervisor in EL2. + * + * Only uses x0..x2 so as to not clobber callee-saved SMCCC registers + * and leave x3 for the caller. + * + * x0: struct kvm_nvhe_init_params PA + */ +SYM_CODE_START_LOCAL(___kvm_hyp_init) + ldr x1, [x0, #NVHE_INIT_STACK_HYP_VA] + mov sp, x1 + + ldr x1, [x0, #NVHE_INIT_MAIR_EL2] + msr mair_el2, x1 + + ldr x1, [x0, #NVHE_INIT_HCR_EL2] + msr hcr_el2, x1 + + mov x2, #HCR_E2H + and x2, x1, x2 + cbz x2, 1f + + // hVHE: Replay the EL2 setup to account for the E2H bit + // TPIDR_EL2 is used to preserve x0 across the macro maze... + isb + msr tpidr_el2, x0 + init_el2_state + finalise_el2_state + mrs x0, tpidr_el2 + +1: + ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] + msr tpidr_el2, x1 + + ldr x1, [x0, #NVHE_INIT_VTTBR] + msr vttbr_el2, x1 + + ldr x1, [x0, #NVHE_INIT_VTCR] + msr vtcr_el2, x1 + + ldr x1, [x0, #NVHE_INIT_PGD_PA] + phys_to_ttbr x2, x1 +alternative_if ARM64_HAS_CNP + orr x2, x2, #TTBR_CNP_BIT +alternative_else_nop_endif + msr ttbr0_el2, x2 + + ldr x0, [x0, #NVHE_INIT_TCR_EL2] + msr tcr_el2, x0 + + isb + + /* Invalidate the stale TLBs from Bootloader */ + tlbi alle2 + tlbi vmalls12e1 + dsb sy + + mov_q x0, INIT_SCTLR_EL2_MMU_ON +alternative_if ARM64_HAS_ADDRESS_AUTH + mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ + SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) + orr x0, x0, x1 +alternative_else_nop_endif + +#ifdef CONFIG_ARM64_BTI_KERNEL +alternative_if ARM64_BTI + orr x0, x0, #SCTLR_EL2_BT +alternative_else_nop_endif +#endif /* CONFIG_ARM64_BTI_KERNEL */ + + msr sctlr_el2, x0 + isb + + /* Set the host vector */ + ldr x0, =__kvm_hyp_host_vector + msr vbar_el2, x0 + + ret +SYM_CODE_END(___kvm_hyp_init) + +/* + * PSCI CPU_ON entry point + * + * x0: struct kvm_nvhe_init_params PA + */ +SYM_CODE_START(kvm_hyp_cpu_entry) + mov x1, #1 // is_cpu_on = true + b __kvm_hyp_init_cpu +SYM_CODE_END(kvm_hyp_cpu_entry) + +/* + * PSCI CPU_SUSPEND / SYSTEM_SUSPEND entry point + * + * x0: struct kvm_nvhe_init_params PA + */ +SYM_CODE_START(kvm_hyp_cpu_resume) + mov x1, #0 // is_cpu_on = false + b __kvm_hyp_init_cpu +SYM_CODE_END(kvm_hyp_cpu_resume) + +/* + * Common code for CPU entry points. Initializes EL2 state and + * installs the hypervisor before handing over to a C handler. + * + * x0: struct kvm_nvhe_init_params PA + * x1: bool is_cpu_on + */ +SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) + mov x28, x0 // Stash arguments + mov x29, x1 + + /* Check that the core was booted in EL2. */ + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL2 + b.eq 2f + + /* The core booted in EL1. KVM cannot be initialized on it. */ +1: wfe + wfi + b 1b + +2: msr SPsel, #1 // We want to use SP_EL{1,2} + + /* Initialize EL2 CPU state to sane values. */ + init_el2_state // Clobbers x0..x2 + finalise_el2_state + __init_el2_nvhe_prepare_eret + + /* Enable MMU, set vectors and stack. */ + mov x0, x28 + bl ___kvm_hyp_init // Clobbers x0..x2 + + /* Leave idmap. */ + mov x0, x29 + ldr x1, =kvm_host_psci_cpu_entry + br x1 +SYM_CODE_END(__kvm_hyp_init_cpu) + +SYM_CODE_START(__kvm_handle_stub_hvc) + /* + * __kvm_handle_stub_hvc called from __host_hvc through branch instruction(br) so + * we need bti j at beginning. + */ + bti j + cmp x0, #HVC_SOFT_RESTART + b.ne 1f + + /* This is where we're about to jump, staying at EL2 */ + msr elr_el2, x1 + mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) + msr spsr_el2, x0 + + /* Shuffle the arguments, and don't come back */ + mov x0, x2 + mov x1, x3 + mov x2, x4 + b reset + +1: cmp x0, #HVC_RESET_VECTORS + b.ne 1f + + /* + * Set the HVC_RESET_VECTORS return code before entering the common + * path so that we do not clobber x0-x2 in case we are coming via + * HVC_SOFT_RESTART. + */ + mov x0, xzr +reset: + /* Reset kvm back to the hyp stub. */ + mov_q x5, INIT_SCTLR_EL2_MMU_OFF + pre_disable_mmu_workaround + msr sctlr_el2, x5 + isb + +alternative_if ARM64_KVM_PROTECTED_MODE + mov_q x5, HCR_HOST_NVHE_FLAGS + msr hcr_el2, x5 +alternative_else_nop_endif + + /* Install stub vectors */ + adr_l x5, __hyp_stub_vectors + msr vbar_el2, x5 + eret + +1: /* Bad stub call */ + mov_q x0, HVC_STUB_ERR + eret + +SYM_CODE_END(__kvm_handle_stub_hvc) + +SYM_FUNC_START(__pkvm_init_switch_pgd) + /* Turn the MMU off */ + pre_disable_mmu_workaround + mrs x2, sctlr_el2 + bic x3, x2, #SCTLR_ELx_M + msr sctlr_el2, x3 + isb + + tlbi alle2 + + /* Install the new pgtables */ + ldr x3, [x0, #NVHE_INIT_PGD_PA] + phys_to_ttbr x4, x3 +alternative_if ARM64_HAS_CNP + orr x4, x4, #TTBR_CNP_BIT +alternative_else_nop_endif + msr ttbr0_el2, x4 + + /* Set the new stack pointer */ + ldr x0, [x0, #NVHE_INIT_STACK_HYP_VA] + mov sp, x0 + + /* And turn the MMU back on! */ + dsb nsh + isb + set_sctlr_el2 x2 + ret x1 +SYM_FUNC_END(__pkvm_init_switch_pgd) + + .popsection diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c new file mode 100644 index 000000000000..2385fd03ed87 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -0,0 +1,438 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 - Google Inc + * Author: Andrew Scull <ascull@google.com> + */ + +#include <hyp/adjust_pc.h> + +#include <asm/pgtable-types.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +#include <nvhe/ffa.h> +#include <nvhe/mem_protect.h> +#include <nvhe/mm.h> +#include <nvhe/pkvm.h> +#include <nvhe/trap_handler.h> + +DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); + +void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt); + +static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + + hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; + + hyp_vcpu->vcpu.arch.sve_state = kern_hyp_va(host_vcpu->arch.sve_state); + hyp_vcpu->vcpu.arch.sve_max_vl = host_vcpu->arch.sve_max_vl; + + hyp_vcpu->vcpu.arch.hw_mmu = host_vcpu->arch.hw_mmu; + + hyp_vcpu->vcpu.arch.hcr_el2 = host_vcpu->arch.hcr_el2; + hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; + hyp_vcpu->vcpu.arch.cptr_el2 = host_vcpu->arch.cptr_el2; + + hyp_vcpu->vcpu.arch.iflags = host_vcpu->arch.iflags; + hyp_vcpu->vcpu.arch.fp_state = host_vcpu->arch.fp_state; + + hyp_vcpu->vcpu.arch.debug_ptr = kern_hyp_va(host_vcpu->arch.debug_ptr); + hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state; + + hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; + + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; +} + +static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3; + struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3; + unsigned int i; + + host_vcpu->arch.ctxt = hyp_vcpu->vcpu.arch.ctxt; + + host_vcpu->arch.hcr_el2 = hyp_vcpu->vcpu.arch.hcr_el2; + host_vcpu->arch.cptr_el2 = hyp_vcpu->vcpu.arch.cptr_el2; + + host_vcpu->arch.fault = hyp_vcpu->vcpu.arch.fault; + + host_vcpu->arch.iflags = hyp_vcpu->vcpu.arch.iflags; + host_vcpu->arch.fp_state = hyp_vcpu->vcpu.arch.fp_state; + + host_cpu_if->vgic_hcr = hyp_cpu_if->vgic_hcr; + for (i = 0; i < hyp_cpu_if->used_lrs; ++i) + host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i]; +} + +static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1); + int ret; + + host_vcpu = kern_hyp_va(host_vcpu); + + if (unlikely(is_protected_kvm_enabled())) { + struct pkvm_hyp_vcpu *hyp_vcpu; + struct kvm *host_kvm; + + host_kvm = kern_hyp_va(host_vcpu->kvm); + hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle, + host_vcpu->vcpu_idx); + if (!hyp_vcpu) { + ret = -EINVAL; + goto out; + } + + flush_hyp_vcpu(hyp_vcpu); + + ret = __kvm_vcpu_run(&hyp_vcpu->vcpu); + + sync_hyp_vcpu(hyp_vcpu); + pkvm_put_hyp_vcpu(hyp_vcpu); + } else { + /* The host is fully trusted, run its vCPU directly. */ + ret = __kvm_vcpu_run(host_vcpu); + } + +out: + cpu_reg(host_ctxt, 1) = ret; +} + +static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); + + __kvm_adjust_pc(kern_hyp_va(vcpu)); +} + +static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt) +{ + __kvm_flush_vm_context(); +} + +static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1); + DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2); + DECLARE_REG(int, level, host_ctxt, 3); + + __kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level); +} + +static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1); + DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2); + DECLARE_REG(int, level, host_ctxt, 3); + + __kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level); +} + +static void +handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1); + DECLARE_REG(phys_addr_t, start, host_ctxt, 2); + DECLARE_REG(unsigned long, pages, host_ctxt, 3); + + __kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages); +} + +static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1); + + __kvm_tlb_flush_vmid(kern_hyp_va(mmu)); +} + +static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1); + + __kvm_flush_cpu_context(kern_hyp_va(mmu)); +} + +static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt) +{ + __kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1)); +} + +static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt) +{ + u64 tmp; + + tmp = read_sysreg_el2(SYS_SCTLR); + tmp |= SCTLR_ELx_DSSBS; + write_sysreg_el2(tmp, SYS_SCTLR); +} + +static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt) +{ + cpu_reg(host_ctxt, 1) = __vgic_v3_get_gic_config(); +} + +static void handle___vgic_v3_read_vmcr(struct kvm_cpu_context *host_ctxt) +{ + cpu_reg(host_ctxt, 1) = __vgic_v3_read_vmcr(); +} + +static void handle___vgic_v3_write_vmcr(struct kvm_cpu_context *host_ctxt) +{ + __vgic_v3_write_vmcr(cpu_reg(host_ctxt, 1)); +} + +static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt) +{ + __vgic_v3_init_lrs(); +} + +static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt) +{ + cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2(); +} + +static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1); + + __vgic_v3_save_aprs(kern_hyp_va(cpu_if)); +} + +static void handle___vgic_v3_restore_aprs(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1); + + __vgic_v3_restore_aprs(kern_hyp_va(cpu_if)); +} + +static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(phys_addr_t, phys, host_ctxt, 1); + DECLARE_REG(unsigned long, size, host_ctxt, 2); + DECLARE_REG(unsigned long, nr_cpus, host_ctxt, 3); + DECLARE_REG(unsigned long *, per_cpu_base, host_ctxt, 4); + DECLARE_REG(u32, hyp_va_bits, host_ctxt, 5); + + /* + * __pkvm_init() will return only if an error occurred, otherwise it + * will tail-call in __pkvm_init_finalise() which will have to deal + * with the host context directly. + */ + cpu_reg(host_ctxt, 1) = __pkvm_init(phys, size, nr_cpus, per_cpu_base, + hyp_va_bits); +} + +static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(enum arm64_hyp_spectre_vector, slot, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = pkvm_cpu_set_vector(slot); +} + +static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, pfn, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn); +} + +static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, pfn, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn); +} + +static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(phys_addr_t, phys, host_ctxt, 1); + DECLARE_REG(size_t, size, host_ctxt, 2); + DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3); + + /* + * __pkvm_create_private_mapping() populates a pointer with the + * hypervisor start address of the allocation. + * + * However, handle___pkvm_create_private_mapping() hypercall crosses the + * EL1/EL2 boundary so the pointer would not be valid in this context. + * + * Instead pass the allocation address as the return value (or return + * ERR_PTR() on failure). + */ + unsigned long haddr; + int err = __pkvm_create_private_mapping(phys, size, prot, &haddr); + + if (err) + haddr = (unsigned long)ERR_PTR(err); + + cpu_reg(host_ctxt, 1) = haddr; +} + +static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt) +{ + cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize(); +} + +static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); + + __pkvm_vcpu_init_traps(kern_hyp_va(vcpu)); +} + +static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1); + DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2); + DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3); + + host_kvm = kern_hyp_va(host_kvm); + cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva); +} + +static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1); + DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2); + DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3); + + host_vcpu = kern_hyp_va(host_vcpu); + cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva); +} + +static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle); +} + +typedef void (*hcall_t)(struct kvm_cpu_context *); + +#define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x + +static const hcall_t host_hcall[] = { + /* ___kvm_hyp_init */ + HANDLE_FUNC(__kvm_get_mdcr_el2), + HANDLE_FUNC(__pkvm_init), + HANDLE_FUNC(__pkvm_create_private_mapping), + HANDLE_FUNC(__pkvm_cpu_set_vector), + HANDLE_FUNC(__kvm_enable_ssbs), + HANDLE_FUNC(__vgic_v3_init_lrs), + HANDLE_FUNC(__vgic_v3_get_gic_config), + HANDLE_FUNC(__pkvm_prot_finalize), + + HANDLE_FUNC(__pkvm_host_share_hyp), + HANDLE_FUNC(__pkvm_host_unshare_hyp), + HANDLE_FUNC(__kvm_adjust_pc), + HANDLE_FUNC(__kvm_vcpu_run), + HANDLE_FUNC(__kvm_flush_vm_context), + HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa), + HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh), + HANDLE_FUNC(__kvm_tlb_flush_vmid), + HANDLE_FUNC(__kvm_tlb_flush_vmid_range), + HANDLE_FUNC(__kvm_flush_cpu_context), + HANDLE_FUNC(__kvm_timer_set_cntvoff), + HANDLE_FUNC(__vgic_v3_read_vmcr), + HANDLE_FUNC(__vgic_v3_write_vmcr), + HANDLE_FUNC(__vgic_v3_save_aprs), + HANDLE_FUNC(__vgic_v3_restore_aprs), + HANDLE_FUNC(__pkvm_vcpu_init_traps), + HANDLE_FUNC(__pkvm_init_vm), + HANDLE_FUNC(__pkvm_init_vcpu), + HANDLE_FUNC(__pkvm_teardown_vm), +}; + +static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(unsigned long, id, host_ctxt, 0); + unsigned long hcall_min = 0; + hcall_t hfn; + + /* + * If pKVM has been initialised then reject any calls to the + * early "privileged" hypercalls. Note that we cannot reject + * calls to __pkvm_prot_finalize for two reasons: (1) The static + * key used to determine initialisation must be toggled prior to + * finalisation and (2) finalisation is performed on a per-CPU + * basis. This is all fine, however, since __pkvm_prot_finalize + * returns -EPERM after the first call for a given CPU. + */ + if (static_branch_unlikely(&kvm_protected_mode_initialized)) + hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize; + + id &= ~ARM_SMCCC_CALL_HINTS; + id -= KVM_HOST_SMCCC_ID(0); + + if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall))) + goto inval; + + hfn = host_hcall[id]; + if (unlikely(!hfn)) + goto inval; + + cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS; + hfn(host_ctxt); + + return; +inval: + cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED; +} + +static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt) +{ + __kvm_hyp_host_forward_smc(host_ctxt); +} + +static void handle_host_smc(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, func_id, host_ctxt, 0); + bool handled; + + func_id &= ~ARM_SMCCC_CALL_HINTS; + + handled = kvm_host_psci_handler(host_ctxt, func_id); + if (!handled) + handled = kvm_host_ffa_handler(host_ctxt, func_id); + if (!handled) + default_host_smc_handler(host_ctxt); + + /* SMC was trapped, move ELR past the current PC. */ + kvm_skip_host_instr(); +} + +void handle_trap(struct kvm_cpu_context *host_ctxt) +{ + u64 esr = read_sysreg_el2(SYS_ESR); + + switch (ESR_ELx_EC(esr)) { + case ESR_ELx_EC_HVC64: + handle_host_hcall(host_ctxt); + break; + case ESR_ELx_EC_SMC64: + handle_host_smc(host_ctxt); + break; + case ESR_ELx_EC_SVE: + if (has_hvhe()) + sysreg_clear_set(cpacr_el1, 0, (CPACR_EL1_ZEN_EL1EN | + CPACR_EL1_ZEN_EL0EN)); + else + sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0); + isb(); + sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2); + break; + case ESR_ELx_EC_IABT_LOW: + case ESR_ELx_EC_DABT_LOW: + handle_host_mem_abort(host_ctxt); + break; + default: + BUG(); + } +} diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c new file mode 100644 index 000000000000..04d194583f1e --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 - Google LLC + * Author: David Brazdil <dbrazdil@google.com> + */ + +#include <asm/kvm_asm.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +/* + * nVHE copy of data structures tracking available CPU cores. + * Only entries for CPUs that were online at KVM init are populated. + * Other CPUs should not be allowed to boot because their features were + * not checked against the finalized system capabilities. + */ +u64 __ro_after_init hyp_cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; + +u64 cpu_logical_map(unsigned int cpu) +{ + BUG_ON(cpu >= ARRAY_SIZE(hyp_cpu_logical_map)); + + return hyp_cpu_logical_map[cpu]; +} + +unsigned long __ro_after_init kvm_arm_hyp_percpu_base[NR_CPUS]; + +unsigned long __hyp_per_cpu_offset(unsigned int cpu) +{ + unsigned long *cpu_base_array; + unsigned long this_cpu_base; + unsigned long elf_base; + + BUG_ON(cpu >= ARRAY_SIZE(kvm_arm_hyp_percpu_base)); + + cpu_base_array = (unsigned long *)&kvm_arm_hyp_percpu_base; + this_cpu_base = kern_hyp_va(cpu_base_array[cpu]); + elf_base = (unsigned long)&__per_cpu_start; + return this_cpu_base - elf_base; +} diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S new file mode 100644 index 000000000000..f4562f417d3f --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020 Google LLC. + * Written by David Brazdil <dbrazdil@google.com> + * + * Linker script used for partial linking of nVHE EL2 object files. + */ + +#include <asm/hyp_image.h> +#include <asm-generic/vmlinux.lds.h> +#include <asm/cache.h> +#include <asm/memory.h> + +SECTIONS { + HYP_SECTION(.idmap.text) + HYP_SECTION(.text) + HYP_SECTION(.data..ro_after_init) + HYP_SECTION(.rodata) + + /* + * .hyp..data..percpu needs to be page aligned to maintain the same + * alignment for when linking into vmlinux. + */ + . = ALIGN(PAGE_SIZE); + BEGIN_HYP_SECTION(.data..percpu) + PERCPU_INPUT(L1_CACHE_BYTES) + END_HYP_SECTION + HYP_SECTION(.bss) +} diff --git a/arch/arm64/kvm/hyp/nvhe/list_debug.c b/arch/arm64/kvm/hyp/nvhe/list_debug.c new file mode 100644 index 000000000000..46a2d4f2b3c6 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/list_debug.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 - Google LLC + * Author: Keir Fraser <keirf@google.com> + */ + +#include <linux/list.h> +#include <linux/bug.h> + +static inline __must_check bool nvhe_check_data_corruption(bool v) +{ + return v; +} + +#define NVHE_CHECK_DATA_CORRUPTION(condition) \ + nvhe_check_data_corruption(({ \ + bool corruption = unlikely(condition); \ + if (corruption) { \ + if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \ + BUG_ON(1); \ + } else \ + WARN_ON(1); \ + } \ + corruption; \ + })) + +/* The predicates checked here are taken from lib/list_debug.c. */ + +__list_valid_slowpath +bool __list_add_valid_or_report(struct list_head *new, struct list_head *prev, + struct list_head *next) +{ + if (NVHE_CHECK_DATA_CORRUPTION(next->prev != prev) || + NVHE_CHECK_DATA_CORRUPTION(prev->next != next) || + NVHE_CHECK_DATA_CORRUPTION(new == prev || new == next)) + return false; + + return true; +} + +__list_valid_slowpath +bool __list_del_entry_valid_or_report(struct list_head *entry) +{ + struct list_head *prev, *next; + + prev = entry->prev; + next = entry->next; + + if (NVHE_CHECK_DATA_CORRUPTION(next == LIST_POISON1) || + NVHE_CHECK_DATA_CORRUPTION(prev == LIST_POISON2) || + NVHE_CHECK_DATA_CORRUPTION(prev->next != entry) || + NVHE_CHECK_DATA_CORRUPTION(next->prev != entry)) + return false; + + return true; +} diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c new file mode 100644 index 000000000000..861c76021a25 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -0,0 +1,1305 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> +#include <asm/stage2_pgtable.h> + +#include <hyp/fault.h> + +#include <nvhe/gfp.h> +#include <nvhe/memory.h> +#include <nvhe/mem_protect.h> +#include <nvhe/mm.h> + +#define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_NOFWB | KVM_PGTABLE_S2_IDMAP) + +struct host_mmu host_mmu; + +static struct hyp_pool host_s2_pool; + +static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm); +#define current_vm (*this_cpu_ptr(&__current_vm)) + +static void guest_lock_component(struct pkvm_hyp_vm *vm) +{ + hyp_spin_lock(&vm->lock); + current_vm = vm; +} + +static void guest_unlock_component(struct pkvm_hyp_vm *vm) +{ + current_vm = NULL; + hyp_spin_unlock(&vm->lock); +} + +static void host_lock_component(void) +{ + hyp_spin_lock(&host_mmu.lock); +} + +static void host_unlock_component(void) +{ + hyp_spin_unlock(&host_mmu.lock); +} + +static void hyp_lock_component(void) +{ + hyp_spin_lock(&pkvm_pgd_lock); +} + +static void hyp_unlock_component(void) +{ + hyp_spin_unlock(&pkvm_pgd_lock); +} + +static void *host_s2_zalloc_pages_exact(size_t size) +{ + void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size)); + + hyp_split_page(hyp_virt_to_page(addr)); + + /* + * The size of concatenated PGDs is always a power of two of PAGE_SIZE, + * so there should be no need to free any of the tail pages to make the + * allocation exact. + */ + WARN_ON(size != (PAGE_SIZE << get_order(size))); + + return addr; +} + +static void *host_s2_zalloc_page(void *pool) +{ + return hyp_alloc_pages(pool, 0); +} + +static void host_s2_get_page(void *addr) +{ + hyp_get_page(&host_s2_pool, addr); +} + +static void host_s2_put_page(void *addr) +{ + hyp_put_page(&host_s2_pool, addr); +} + +static void host_s2_free_unlinked_table(void *addr, s8 level) +{ + kvm_pgtable_stage2_free_unlinked(&host_mmu.mm_ops, addr, level); +} + +static int prepare_s2_pool(void *pgt_pool_base) +{ + unsigned long nr_pages, pfn; + int ret; + + pfn = hyp_virt_to_pfn(pgt_pool_base); + nr_pages = host_s2_pgtable_pages(); + ret = hyp_pool_init(&host_s2_pool, pfn, nr_pages, 0); + if (ret) + return ret; + + host_mmu.mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_pages_exact = host_s2_zalloc_pages_exact, + .zalloc_page = host_s2_zalloc_page, + .free_unlinked_table = host_s2_free_unlinked_table, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .page_count = hyp_page_count, + .get_page = host_s2_get_page, + .put_page = host_s2_put_page, + }; + + return 0; +} + +static void prepare_host_vtcr(void) +{ + u32 parange, phys_shift; + + /* The host stage 2 is id-mapped, so use parange for T0SZ */ + parange = kvm_get_parange(id_aa64mmfr0_el1_sys_val); + phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange); + + host_mmu.arch.mmu.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val, + id_aa64mmfr1_el1_sys_val, phys_shift); +} + +static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot); + +int kvm_host_prepare_stage2(void *pgt_pool_base) +{ + struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu; + int ret; + + prepare_host_vtcr(); + hyp_spin_lock_init(&host_mmu.lock); + mmu->arch = &host_mmu.arch; + + ret = prepare_s2_pool(pgt_pool_base); + if (ret) + return ret; + + ret = __kvm_pgtable_stage2_init(&host_mmu.pgt, mmu, + &host_mmu.mm_ops, KVM_HOST_S2_FLAGS, + host_stage2_force_pte_cb); + if (ret) + return ret; + + mmu->pgd_phys = __hyp_pa(host_mmu.pgt.pgd); + mmu->pgt = &host_mmu.pgt; + atomic64_set(&mmu->vmid.id, 0); + + return 0; +} + +static bool guest_stage2_force_pte_cb(u64 addr, u64 end, + enum kvm_pgtable_prot prot) +{ + return true; +} + +static void *guest_s2_zalloc_pages_exact(size_t size) +{ + void *addr = hyp_alloc_pages(¤t_vm->pool, get_order(size)); + + WARN_ON(size != (PAGE_SIZE << get_order(size))); + hyp_split_page(hyp_virt_to_page(addr)); + + return addr; +} + +static void guest_s2_free_pages_exact(void *addr, unsigned long size) +{ + u8 order = get_order(size); + unsigned int i; + + for (i = 0; i < (1 << order); i++) + hyp_put_page(¤t_vm->pool, addr + (i * PAGE_SIZE)); +} + +static void *guest_s2_zalloc_page(void *mc) +{ + struct hyp_page *p; + void *addr; + + addr = hyp_alloc_pages(¤t_vm->pool, 0); + if (addr) + return addr; + + addr = pop_hyp_memcache(mc, hyp_phys_to_virt); + if (!addr) + return addr; + + memset(addr, 0, PAGE_SIZE); + p = hyp_virt_to_page(addr); + memset(p, 0, sizeof(*p)); + p->refcount = 1; + + return addr; +} + +static void guest_s2_get_page(void *addr) +{ + hyp_get_page(¤t_vm->pool, addr); +} + +static void guest_s2_put_page(void *addr) +{ + hyp_put_page(¤t_vm->pool, addr); +} + +static void clean_dcache_guest_page(void *va, size_t size) +{ + __clean_dcache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +static void invalidate_icache_guest_page(void *va, size_t size) +{ + __invalidate_icache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd) +{ + struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu; + unsigned long nr_pages; + int ret; + + nr_pages = kvm_pgtable_stage2_pgd_size(mmu->vtcr) >> PAGE_SHIFT; + ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0); + if (ret) + return ret; + + hyp_spin_lock_init(&vm->lock); + vm->mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_pages_exact = guest_s2_zalloc_pages_exact, + .free_pages_exact = guest_s2_free_pages_exact, + .zalloc_page = guest_s2_zalloc_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .page_count = hyp_page_count, + .get_page = guest_s2_get_page, + .put_page = guest_s2_put_page, + .dcache_clean_inval_poc = clean_dcache_guest_page, + .icache_inval_pou = invalidate_icache_guest_page, + }; + + guest_lock_component(vm); + ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, + guest_stage2_force_pte_cb); + guest_unlock_component(vm); + if (ret) + return ret; + + vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd); + + return 0; +} + +void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc) +{ + void *addr; + + /* Dump all pgtable pages in the hyp_pool */ + guest_lock_component(vm); + kvm_pgtable_stage2_destroy(&vm->pgt); + vm->kvm.arch.mmu.pgd_phys = 0ULL; + guest_unlock_component(vm); + + /* Drain the hyp_pool into the memcache */ + addr = hyp_alloc_pages(&vm->pool, 0); + while (addr) { + memset(hyp_virt_to_page(addr), 0, sizeof(struct hyp_page)); + push_hyp_memcache(mc, addr, hyp_virt_to_phys); + WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(addr), 1)); + addr = hyp_alloc_pages(&vm->pool, 0); + } +} + +int __pkvm_prot_finalize(void) +{ + struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu; + struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); + + if (params->hcr_el2 & HCR_VM) + return -EPERM; + + params->vttbr = kvm_get_vttbr(mmu); + params->vtcr = mmu->vtcr; + params->hcr_el2 |= HCR_VM; + + /* + * The CMO below not only cleans the updated params to the + * PoC, but also provides the DSB that ensures ongoing + * page-table walks that have started before we trapped to EL2 + * have completed. + */ + kvm_flush_dcache_to_poc(params, sizeof(*params)); + + write_sysreg(params->hcr_el2, hcr_el2); + __load_stage2(&host_mmu.arch.mmu, &host_mmu.arch); + + /* + * Make sure to have an ISB before the TLB maintenance below but only + * when __load_stage2() doesn't include one already. + */ + asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT)); + + /* Invalidate stale HCR bits that may be cached in TLBs */ + __tlbi(vmalls12e1); + dsb(nsh); + isb(); + + return 0; +} + +static int host_stage2_unmap_dev_all(void) +{ + struct kvm_pgtable *pgt = &host_mmu.pgt; + struct memblock_region *reg; + u64 addr = 0; + int i, ret; + + /* Unmap all non-memory regions to recycle the pages */ + for (i = 0; i < hyp_memblock_nr; i++, addr = reg->base + reg->size) { + reg = &hyp_memory[i]; + ret = kvm_pgtable_stage2_unmap(pgt, addr, reg->base - addr); + if (ret) + return ret; + } + return kvm_pgtable_stage2_unmap(pgt, addr, BIT(pgt->ia_bits) - addr); +} + +struct kvm_mem_range { + u64 start; + u64 end; +}; + +static struct memblock_region *find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) +{ + int cur, left = 0, right = hyp_memblock_nr; + struct memblock_region *reg; + phys_addr_t end; + + range->start = 0; + range->end = ULONG_MAX; + + /* The list of memblock regions is sorted, binary search it */ + while (left < right) { + cur = (left + right) >> 1; + reg = &hyp_memory[cur]; + end = reg->base + reg->size; + if (addr < reg->base) { + right = cur; + range->end = reg->base; + } else if (addr >= end) { + left = cur + 1; + range->start = end; + } else { + range->start = reg->base; + range->end = end; + return reg; + } + } + + return NULL; +} + +bool addr_is_memory(phys_addr_t phys) +{ + struct kvm_mem_range range; + + return !!find_mem_range(phys, &range); +} + +static bool addr_is_allowed_memory(phys_addr_t phys) +{ + struct memblock_region *reg; + struct kvm_mem_range range; + + reg = find_mem_range(phys, &range); + + return reg && !(reg->flags & MEMBLOCK_NOMAP); +} + +static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range) +{ + return range->start <= addr && addr < range->end; +} + +static bool range_is_memory(u64 start, u64 end) +{ + struct kvm_mem_range r; + + if (!find_mem_range(start, &r)) + return false; + + return is_in_mem_range(end - 1, &r); +} + +static inline int __host_stage2_idmap(u64 start, u64 end, + enum kvm_pgtable_prot prot) +{ + return kvm_pgtable_stage2_map(&host_mmu.pgt, start, end - start, start, + prot, &host_s2_pool, 0); +} + +/* + * The pool has been provided with enough pages to cover all of memory with + * page granularity, but it is difficult to know how much of the MMIO range + * we will need to cover upfront, so we may need to 'recycle' the pages if we + * run out. + */ +#define host_stage2_try(fn, ...) \ + ({ \ + int __ret; \ + hyp_assert_lock_held(&host_mmu.lock); \ + __ret = fn(__VA_ARGS__); \ + if (__ret == -ENOMEM) { \ + __ret = host_stage2_unmap_dev_all(); \ + if (!__ret) \ + __ret = fn(__VA_ARGS__); \ + } \ + __ret; \ + }) + +static inline bool range_included(struct kvm_mem_range *child, + struct kvm_mem_range *parent) +{ + return parent->start <= child->start && child->end <= parent->end; +} + +static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range) +{ + struct kvm_mem_range cur; + kvm_pte_t pte; + s8 level; + int ret; + + hyp_assert_lock_held(&host_mmu.lock); + ret = kvm_pgtable_get_leaf(&host_mmu.pgt, addr, &pte, &level); + if (ret) + return ret; + + if (kvm_pte_valid(pte)) + return -EAGAIN; + + if (pte) + return -EPERM; + + do { + u64 granule = kvm_granule_size(level); + cur.start = ALIGN_DOWN(addr, granule); + cur.end = cur.start + granule; + level++; + } while ((level <= KVM_PGTABLE_LAST_LEVEL) && + !(kvm_level_supports_block_mapping(level) && + range_included(&cur, range))); + + *range = cur; + + return 0; +} + +int host_stage2_idmap_locked(phys_addr_t addr, u64 size, + enum kvm_pgtable_prot prot) +{ + return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot); +} + +int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) +{ + return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt, + addr, size, &host_s2_pool, owner_id); +} + +static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot) +{ + /* + * Block mappings must be used with care in the host stage-2 as a + * kvm_pgtable_stage2_map() operation targeting a page in the range of + * an existing block will delete the block under the assumption that + * mappings in the rest of the block range can always be rebuilt lazily. + * That assumption is correct for the host stage-2 with RWX mappings + * targeting memory or RW mappings targeting MMIO ranges (see + * host_stage2_idmap() below which implements some of the host memory + * abort logic). However, this is not safe for any other mappings where + * the host stage-2 page-table is in fact the only place where this + * state is stored. In all those cases, it is safer to use page-level + * mappings, hence avoiding to lose the state because of side-effects in + * kvm_pgtable_stage2_map(). + */ + if (range_is_memory(addr, end)) + return prot != PKVM_HOST_MEM_PROT; + else + return prot != PKVM_HOST_MMIO_PROT; +} + +static int host_stage2_idmap(u64 addr) +{ + struct kvm_mem_range range; + bool is_memory = !!find_mem_range(addr, &range); + enum kvm_pgtable_prot prot; + int ret; + + prot = is_memory ? PKVM_HOST_MEM_PROT : PKVM_HOST_MMIO_PROT; + + host_lock_component(); + ret = host_stage2_adjust_range(addr, &range); + if (ret) + goto unlock; + + ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot); +unlock: + host_unlock_component(); + + return ret; +} + +void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt) +{ + struct kvm_vcpu_fault_info fault; + u64 esr, addr; + int ret = 0; + + esr = read_sysreg_el2(SYS_ESR); + BUG_ON(!__get_fault_info(esr, &fault)); + + addr = (fault.hpfar_el2 & HPFAR_MASK) << 8; + ret = host_stage2_idmap(addr); + BUG_ON(ret && ret != -EAGAIN); +} + +struct pkvm_mem_transition { + u64 nr_pages; + + struct { + enum pkvm_component_id id; + /* Address in the initiator's address space */ + u64 addr; + + union { + struct { + /* Address in the completer's address space */ + u64 completer_addr; + } host; + struct { + u64 completer_addr; + } hyp; + }; + } initiator; + + struct { + enum pkvm_component_id id; + } completer; +}; + +struct pkvm_mem_share { + const struct pkvm_mem_transition tx; + const enum kvm_pgtable_prot completer_prot; +}; + +struct pkvm_mem_donation { + const struct pkvm_mem_transition tx; +}; + +struct check_walk_data { + enum pkvm_page_state desired; + enum pkvm_page_state (*get_page_state)(kvm_pte_t pte, u64 addr); +}; + +static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct check_walk_data *d = ctx->arg; + + return d->get_page_state(ctx->old, ctx->addr) == d->desired ? 0 : -EPERM; +} + +static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size, + struct check_walk_data *data) +{ + struct kvm_pgtable_walker walker = { + .cb = __check_page_state_visitor, + .arg = data, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + + return kvm_pgtable_walk(pgt, addr, size, &walker); +} + +static enum pkvm_page_state host_get_page_state(kvm_pte_t pte, u64 addr) +{ + if (!addr_is_allowed_memory(addr)) + return PKVM_NOPAGE; + + if (!kvm_pte_valid(pte) && pte) + return PKVM_NOPAGE; + + return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte)); +} + +static int __host_check_page_state_range(u64 addr, u64 size, + enum pkvm_page_state state) +{ + struct check_walk_data d = { + .desired = state, + .get_page_state = host_get_page_state, + }; + + hyp_assert_lock_held(&host_mmu.lock); + return check_page_state_range(&host_mmu.pgt, addr, size, &d); +} + +static int __host_set_page_state_range(u64 addr, u64 size, + enum pkvm_page_state state) +{ + enum kvm_pgtable_prot prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, state); + + return host_stage2_idmap_locked(addr, size, prot); +} + +static int host_request_owned_transition(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.host.completer_addr; + return __host_check_page_state_range(addr, size, PKVM_PAGE_OWNED); +} + +static int host_request_unshare(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.host.completer_addr; + return __host_check_page_state_range(addr, size, PKVM_PAGE_SHARED_OWNED); +} + +static int host_initiate_share(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.host.completer_addr; + return __host_set_page_state_range(addr, size, PKVM_PAGE_SHARED_OWNED); +} + +static int host_initiate_unshare(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.host.completer_addr; + return __host_set_page_state_range(addr, size, PKVM_PAGE_OWNED); +} + +static int host_initiate_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u8 owner_id = tx->completer.id; + u64 size = tx->nr_pages * PAGE_SIZE; + + *completer_addr = tx->initiator.host.completer_addr; + return host_stage2_set_owner_locked(tx->initiator.addr, size, owner_id); +} + +static bool __host_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx) +{ + return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) || + tx->initiator.id != PKVM_ID_HYP); +} + +static int __host_ack_transition(u64 addr, const struct pkvm_mem_transition *tx, + enum pkvm_page_state state) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (__host_ack_skip_pgtable_check(tx)) + return 0; + + return __host_check_page_state_range(addr, size, state); +} + +static int host_ack_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + return __host_ack_transition(addr, tx, PKVM_NOPAGE); +} + +static int host_complete_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u8 host_id = tx->completer.id; + + return host_stage2_set_owner_locked(addr, size, host_id); +} + +static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte, u64 addr) +{ + if (!kvm_pte_valid(pte)) + return PKVM_NOPAGE; + + return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte)); +} + +static int __hyp_check_page_state_range(u64 addr, u64 size, + enum pkvm_page_state state) +{ + struct check_walk_data d = { + .desired = state, + .get_page_state = hyp_get_page_state, + }; + + hyp_assert_lock_held(&pkvm_pgd_lock); + return check_page_state_range(&pkvm_pgtable, addr, size, &d); +} + +static int hyp_request_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + u64 addr = tx->initiator.addr; + + *completer_addr = tx->initiator.hyp.completer_addr; + return __hyp_check_page_state_range(addr, size, PKVM_PAGE_OWNED); +} + +static int hyp_initiate_donation(u64 *completer_addr, + const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + int ret; + + *completer_addr = tx->initiator.hyp.completer_addr; + ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, tx->initiator.addr, size); + return (ret != size) ? -EFAULT : 0; +} + +static bool __hyp_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx) +{ + return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) || + tx->initiator.id != PKVM_ID_HOST); +} + +static int hyp_ack_share(u64 addr, const struct pkvm_mem_transition *tx, + enum kvm_pgtable_prot perms) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (perms != PAGE_HYP) + return -EPERM; + + if (__hyp_ack_skip_pgtable_check(tx)) + return 0; + + return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE); +} + +static int hyp_ack_unshare(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (tx->initiator.id == PKVM_ID_HOST && hyp_page_count((void *)addr)) + return -EBUSY; + + if (__hyp_ack_skip_pgtable_check(tx)) + return 0; + + return __hyp_check_page_state_range(addr, size, + PKVM_PAGE_SHARED_BORROWED); +} + +static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + + if (__hyp_ack_skip_pgtable_check(tx)) + return 0; + + return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE); +} + +static int hyp_complete_share(u64 addr, const struct pkvm_mem_transition *tx, + enum kvm_pgtable_prot perms) +{ + void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE); + enum kvm_pgtable_prot prot; + + prot = pkvm_mkstate(perms, PKVM_PAGE_SHARED_BORROWED); + return pkvm_create_mappings_locked(start, end, prot); +} + +static int hyp_complete_unshare(u64 addr, const struct pkvm_mem_transition *tx) +{ + u64 size = tx->nr_pages * PAGE_SIZE; + int ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, addr, size); + + return (ret != size) ? -EFAULT : 0; +} + +static int hyp_complete_donation(u64 addr, + const struct pkvm_mem_transition *tx) +{ + void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE); + enum kvm_pgtable_prot prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_OWNED); + + return pkvm_create_mappings_locked(start, end, prot); +} + +static int check_share(struct pkvm_mem_share *share) +{ + const struct pkvm_mem_transition *tx = &share->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_request_owned_transition(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HYP: + ret = hyp_ack_share(completer_addr, tx, share->completer_prot); + break; + case PKVM_ID_FFA: + /* + * We only check the host; the secure side will check the other + * end when we forward the FFA call. + */ + ret = 0; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static int __do_share(struct pkvm_mem_share *share) +{ + const struct pkvm_mem_transition *tx = &share->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_initiate_share(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HYP: + ret = hyp_complete_share(completer_addr, tx, share->completer_prot); + break; + case PKVM_ID_FFA: + /* + * We're not responsible for any secure page-tables, so there's + * nothing to do here. + */ + ret = 0; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +/* + * do_share(): + * + * The page owner grants access to another component with a given set + * of permissions. + * + * Initiator: OWNED => SHARED_OWNED + * Completer: NOPAGE => SHARED_BORROWED + */ +static int do_share(struct pkvm_mem_share *share) +{ + int ret; + + ret = check_share(share); + if (ret) + return ret; + + return WARN_ON(__do_share(share)); +} + +static int check_unshare(struct pkvm_mem_share *share) +{ + const struct pkvm_mem_transition *tx = &share->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_request_unshare(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HYP: + ret = hyp_ack_unshare(completer_addr, tx); + break; + case PKVM_ID_FFA: + /* See check_share() */ + ret = 0; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static int __do_unshare(struct pkvm_mem_share *share) +{ + const struct pkvm_mem_transition *tx = &share->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_initiate_unshare(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HYP: + ret = hyp_complete_unshare(completer_addr, tx); + break; + case PKVM_ID_FFA: + /* See __do_share() */ + ret = 0; + break; + default: + ret = -EINVAL; + } + + return ret; +} + +/* + * do_unshare(): + * + * The page owner revokes access from another component for a range of + * pages which were previously shared using do_share(). + * + * Initiator: SHARED_OWNED => OWNED + * Completer: SHARED_BORROWED => NOPAGE + */ +static int do_unshare(struct pkvm_mem_share *share) +{ + int ret; + + ret = check_unshare(share); + if (ret) + return ret; + + return WARN_ON(__do_unshare(share)); +} + +static int check_donation(struct pkvm_mem_donation *donation) +{ + const struct pkvm_mem_transition *tx = &donation->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_request_owned_transition(&completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_request_donation(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HOST: + ret = host_ack_donation(completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_ack_donation(completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +static int __do_donate(struct pkvm_mem_donation *donation) +{ + const struct pkvm_mem_transition *tx = &donation->tx; + u64 completer_addr; + int ret; + + switch (tx->initiator.id) { + case PKVM_ID_HOST: + ret = host_initiate_donation(&completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_initiate_donation(&completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + if (ret) + return ret; + + switch (tx->completer.id) { + case PKVM_ID_HOST: + ret = host_complete_donation(completer_addr, tx); + break; + case PKVM_ID_HYP: + ret = hyp_complete_donation(completer_addr, tx); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +/* + * do_donate(): + * + * The page owner transfers ownership to another component, losing access + * as a consequence. + * + * Initiator: OWNED => NOPAGE + * Completer: NOPAGE => OWNED + */ +static int do_donate(struct pkvm_mem_donation *donation) +{ + int ret; + + ret = check_donation(donation); + if (ret) + return ret; + + return WARN_ON(__do_donate(donation)); +} + +int __pkvm_host_share_hyp(u64 pfn) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_share share = { + .tx = { + .nr_pages = 1, + .initiator = { + .id = PKVM_ID_HOST, + .addr = host_addr, + .host = { + .completer_addr = hyp_addr, + }, + }, + .completer = { + .id = PKVM_ID_HYP, + }, + }, + .completer_prot = PAGE_HYP, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_share(&share); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int __pkvm_host_unshare_hyp(u64 pfn) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_share share = { + .tx = { + .nr_pages = 1, + .initiator = { + .id = PKVM_ID_HOST, + .addr = host_addr, + .host = { + .completer_addr = hyp_addr, + }, + }, + .completer = { + .id = PKVM_ID_HYP, + }, + }, + .completer_prot = PAGE_HYP, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_unshare(&share); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_donation donation = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = host_addr, + .host = { + .completer_addr = hyp_addr, + }, + }, + .completer = { + .id = PKVM_ID_HYP, + }, + }, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_donate(&donation); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_donation donation = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HYP, + .addr = hyp_addr, + .hyp = { + .completer_addr = host_addr, + }, + }, + .completer = { + .id = PKVM_ID_HOST, + }, + }, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_donate(&donation); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +int hyp_pin_shared_mem(void *from, void *to) +{ + u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE); + u64 end = PAGE_ALIGN((u64)to); + u64 size = end - start; + int ret; + + host_lock_component(); + hyp_lock_component(); + + ret = __host_check_page_state_range(__hyp_pa(start), size, + PKVM_PAGE_SHARED_OWNED); + if (ret) + goto unlock; + + ret = __hyp_check_page_state_range(start, size, + PKVM_PAGE_SHARED_BORROWED); + if (ret) + goto unlock; + + for (cur = start; cur < end; cur += PAGE_SIZE) + hyp_page_ref_inc(hyp_virt_to_page(cur)); + +unlock: + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} + +void hyp_unpin_shared_mem(void *from, void *to) +{ + u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE); + u64 end = PAGE_ALIGN((u64)to); + + host_lock_component(); + hyp_lock_component(); + + for (cur = start; cur < end; cur += PAGE_SIZE) + hyp_page_ref_dec(hyp_virt_to_page(cur)); + + hyp_unlock_component(); + host_unlock_component(); +} + +int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages) +{ + int ret; + struct pkvm_mem_share share = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = hyp_pfn_to_phys(pfn), + }, + .completer = { + .id = PKVM_ID_FFA, + }, + }, + }; + + host_lock_component(); + ret = do_share(&share); + host_unlock_component(); + + return ret; +} + +int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) +{ + int ret; + struct pkvm_mem_share share = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = hyp_pfn_to_phys(pfn), + }, + .completer = { + .id = PKVM_ID_FFA, + }, + }, + }; + + host_lock_component(); + ret = do_unshare(&share); + host_unlock_component(); + + return ret; +} diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c new file mode 100644 index 000000000000..8850b591d775 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/mm.c @@ -0,0 +1,423 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> +#include <asm/spectre.h> + +#include <nvhe/early_alloc.h> +#include <nvhe/gfp.h> +#include <nvhe/memory.h> +#include <nvhe/mem_protect.h> +#include <nvhe/mm.h> +#include <nvhe/spinlock.h> + +struct kvm_pgtable pkvm_pgtable; +hyp_spinlock_t pkvm_pgd_lock; + +struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS]; +unsigned int hyp_memblock_nr; + +static u64 __io_map_base; + +struct hyp_fixmap_slot { + u64 addr; + kvm_pte_t *ptep; +}; +static DEFINE_PER_CPU(struct hyp_fixmap_slot, fixmap_slots); + +static int __pkvm_create_mappings(unsigned long start, unsigned long size, + unsigned long phys, enum kvm_pgtable_prot prot) +{ + int err; + + hyp_spin_lock(&pkvm_pgd_lock); + err = kvm_pgtable_hyp_map(&pkvm_pgtable, start, size, phys, prot); + hyp_spin_unlock(&pkvm_pgd_lock); + + return err; +} + +static int __pkvm_alloc_private_va_range(unsigned long start, size_t size) +{ + unsigned long cur; + + hyp_assert_lock_held(&pkvm_pgd_lock); + + if (!start || start < __io_map_base) + return -EINVAL; + + /* The allocated size is always a multiple of PAGE_SIZE */ + cur = start + PAGE_ALIGN(size); + + /* Are we overflowing on the vmemmap ? */ + if (cur > __hyp_vmemmap) + return -ENOMEM; + + __io_map_base = cur; + + return 0; +} + +/** + * pkvm_alloc_private_va_range - Allocates a private VA range. + * @size: The size of the VA range to reserve. + * @haddr: The hypervisor virtual start address of the allocation. + * + * The private virtual address (VA) range is allocated above __io_map_base + * and aligned based on the order of @size. + * + * Return: 0 on success or negative error code on failure. + */ +int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr) +{ + unsigned long addr; + int ret; + + hyp_spin_lock(&pkvm_pgd_lock); + addr = __io_map_base; + ret = __pkvm_alloc_private_va_range(addr, size); + hyp_spin_unlock(&pkvm_pgd_lock); + + *haddr = addr; + + return ret; +} + +int __pkvm_create_private_mapping(phys_addr_t phys, size_t size, + enum kvm_pgtable_prot prot, + unsigned long *haddr) +{ + unsigned long addr; + int err; + + size = PAGE_ALIGN(size + offset_in_page(phys)); + err = pkvm_alloc_private_va_range(size, &addr); + if (err) + return err; + + err = __pkvm_create_mappings(addr, size, phys, prot); + if (err) + return err; + + *haddr = addr + offset_in_page(phys); + return err; +} + +int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot) +{ + unsigned long start = (unsigned long)from; + unsigned long end = (unsigned long)to; + unsigned long virt_addr; + phys_addr_t phys; + + hyp_assert_lock_held(&pkvm_pgd_lock); + + start = start & PAGE_MASK; + end = PAGE_ALIGN(end); + + for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { + int err; + + phys = hyp_virt_to_phys((void *)virt_addr); + err = kvm_pgtable_hyp_map(&pkvm_pgtable, virt_addr, PAGE_SIZE, + phys, prot); + if (err) + return err; + } + + return 0; +} + +int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot) +{ + int ret; + + hyp_spin_lock(&pkvm_pgd_lock); + ret = pkvm_create_mappings_locked(from, to, prot); + hyp_spin_unlock(&pkvm_pgd_lock); + + return ret; +} + +int hyp_back_vmemmap(phys_addr_t back) +{ + unsigned long i, start, size, end = 0; + int ret; + + for (i = 0; i < hyp_memblock_nr; i++) { + start = hyp_memory[i].base; + start = ALIGN_DOWN((u64)hyp_phys_to_page(start), PAGE_SIZE); + /* + * The beginning of the hyp_vmemmap region for the current + * memblock may already be backed by the page backing the end + * the previous region, so avoid mapping it twice. + */ + start = max(start, end); + + end = hyp_memory[i].base + hyp_memory[i].size; + end = PAGE_ALIGN((u64)hyp_phys_to_page(end)); + if (start >= end) + continue; + + size = end - start; + ret = __pkvm_create_mappings(start, size, back, PAGE_HYP); + if (ret) + return ret; + + memset(hyp_phys_to_virt(back), 0, size); + back += size; + } + + return 0; +} + +static void *__hyp_bp_vect_base; +int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot) +{ + void *vector; + + switch (slot) { + case HYP_VECTOR_DIRECT: { + vector = __kvm_hyp_vector; + break; + } + case HYP_VECTOR_SPECTRE_DIRECT: { + vector = __bp_harden_hyp_vecs; + break; + } + case HYP_VECTOR_INDIRECT: + case HYP_VECTOR_SPECTRE_INDIRECT: { + vector = (void *)__hyp_bp_vect_base; + break; + } + default: + return -EINVAL; + } + + vector = __kvm_vector_slot2addr(vector, slot); + *this_cpu_ptr(&kvm_hyp_vector) = (unsigned long)vector; + + return 0; +} + +int hyp_map_vectors(void) +{ + phys_addr_t phys; + unsigned long bp_base; + int ret; + + if (!kvm_system_needs_idmapped_vectors()) { + __hyp_bp_vect_base = __bp_harden_hyp_vecs; + return 0; + } + + phys = __hyp_pa(__bp_harden_hyp_vecs); + ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ, + PAGE_HYP_EXEC, &bp_base); + if (ret) + return ret; + + __hyp_bp_vect_base = (void *)bp_base; + + return 0; +} + +void *hyp_fixmap_map(phys_addr_t phys) +{ + struct hyp_fixmap_slot *slot = this_cpu_ptr(&fixmap_slots); + kvm_pte_t pte, *ptep = slot->ptep; + + pte = *ptep; + pte &= ~kvm_phys_to_pte(KVM_PHYS_INVALID); + pte |= kvm_phys_to_pte(phys) | KVM_PTE_VALID; + WRITE_ONCE(*ptep, pte); + dsb(ishst); + + return (void *)slot->addr; +} + +static void fixmap_clear_slot(struct hyp_fixmap_slot *slot) +{ + kvm_pte_t *ptep = slot->ptep; + u64 addr = slot->addr; + + WRITE_ONCE(*ptep, *ptep & ~KVM_PTE_VALID); + + /* + * Irritatingly, the architecture requires that we use inner-shareable + * broadcast TLB invalidation here in case another CPU speculates + * through our fixmap and decides to create an "amalagamation of the + * values held in the TLB" due to the apparent lack of a + * break-before-make sequence. + * + * https://lore.kernel.org/kvm/20221017115209.2099-1-will@kernel.org/T/#mf10dfbaf1eaef9274c581b81c53758918c1d0f03 + */ + dsb(ishst); + __tlbi_level(vale2is, __TLBI_VADDR(addr, 0), KVM_PGTABLE_LAST_LEVEL); + dsb(ish); + isb(); +} + +void hyp_fixmap_unmap(void) +{ + fixmap_clear_slot(this_cpu_ptr(&fixmap_slots)); +} + +static int __create_fixmap_slot_cb(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct hyp_fixmap_slot *slot = per_cpu_ptr(&fixmap_slots, (u64)ctx->arg); + + if (!kvm_pte_valid(ctx->old) || ctx->level != KVM_PGTABLE_LAST_LEVEL) + return -EINVAL; + + slot->addr = ctx->addr; + slot->ptep = ctx->ptep; + + /* + * Clear the PTE, but keep the page-table page refcount elevated to + * prevent it from ever being freed. This lets us manipulate the PTEs + * by hand safely without ever needing to allocate memory. + */ + fixmap_clear_slot(slot); + + return 0; +} + +static int create_fixmap_slot(u64 addr, u64 cpu) +{ + struct kvm_pgtable_walker walker = { + .cb = __create_fixmap_slot_cb, + .flags = KVM_PGTABLE_WALK_LEAF, + .arg = (void *)cpu, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, addr, PAGE_SIZE, &walker); +} + +int hyp_create_pcpu_fixmap(void) +{ + unsigned long addr, i; + int ret; + + for (i = 0; i < hyp_nr_cpus; i++) { + ret = pkvm_alloc_private_va_range(PAGE_SIZE, &addr); + if (ret) + return ret; + + ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, PAGE_SIZE, + __hyp_pa(__hyp_bss_start), PAGE_HYP); + if (ret) + return ret; + + ret = create_fixmap_slot(addr, i); + if (ret) + return ret; + } + + return 0; +} + +int hyp_create_idmap(u32 hyp_va_bits) +{ + unsigned long start, end; + + start = hyp_virt_to_phys((void *)__hyp_idmap_text_start); + start = ALIGN_DOWN(start, PAGE_SIZE); + + end = hyp_virt_to_phys((void *)__hyp_idmap_text_end); + end = ALIGN(end, PAGE_SIZE); + + /* + * One half of the VA space is reserved to linearly map portions of + * memory -- see va_layout.c for more details. The other half of the VA + * space contains the trampoline page, and needs some care. Split that + * second half in two and find the quarter of VA space not conflicting + * with the idmap to place the IOs and the vmemmap. IOs use the lower + * half of the quarter and the vmemmap the upper half. + */ + __io_map_base = start & BIT(hyp_va_bits - 2); + __io_map_base ^= BIT(hyp_va_bits - 2); + __hyp_vmemmap = __io_map_base | BIT(hyp_va_bits - 3); + + return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC); +} + +int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr) +{ + unsigned long addr, prev_base; + size_t size; + int ret; + + hyp_spin_lock(&pkvm_pgd_lock); + + prev_base = __io_map_base; + /* + * Efficient stack verification using the PAGE_SHIFT bit implies + * an alignment of our allocation on the order of the size. + */ + size = PAGE_SIZE * 2; + addr = ALIGN(__io_map_base, size); + + ret = __pkvm_alloc_private_va_range(addr, size); + if (!ret) { + /* + * Since the stack grows downwards, map the stack to the page + * at the higher address and leave the lower guard page + * unbacked. + * + * Any valid stack address now has the PAGE_SHIFT bit as 1 + * and addresses corresponding to the guard page have the + * PAGE_SHIFT bit as 0 - this is used for overflow detection. + */ + ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr + PAGE_SIZE, + PAGE_SIZE, phys, PAGE_HYP); + if (ret) + __io_map_base = prev_base; + } + hyp_spin_unlock(&pkvm_pgd_lock); + + *haddr = addr + size; + + return ret; +} + +static void *admit_host_page(void *arg) +{ + struct kvm_hyp_memcache *host_mc = arg; + + if (!host_mc->nr_pages) + return NULL; + + /* + * The host still owns the pages in its memcache, so we need to go + * through a full host-to-hyp donation cycle to change it. Fortunately, + * __pkvm_host_donate_hyp() takes care of races for us, so if it + * succeeds we're good to go. + */ + if (__pkvm_host_donate_hyp(hyp_phys_to_pfn(host_mc->head), 1)) + return NULL; + + return pop_hyp_memcache(host_mc, hyp_phys_to_virt); +} + +/* Refill our local memcache by popping pages from the one provided by the host. */ +int refill_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages, + struct kvm_hyp_memcache *host_mc) +{ + struct kvm_hyp_memcache tmp = *host_mc; + int ret; + + ret = __topup_hyp_memcache(mc, min_pages, admit_host_page, + hyp_virt_to_phys, &tmp); + *host_mc = tmp; + + return ret; +} diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c new file mode 100644 index 000000000000..e691290d3765 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <asm/kvm_hyp.h> +#include <nvhe/gfp.h> + +u64 __hyp_vmemmap; + +/* + * Index the hyp_vmemmap to find a potential buddy page, but make no assumption + * about its current state. + * + * Example buddy-tree for a 4-pages physically contiguous pool: + * + * o : Page 3 + * / + * o-o : Page 2 + * / + * / o : Page 1 + * / / + * o---o-o : Page 0 + * Order 2 1 0 + * + * Example of requests on this pool: + * __find_buddy_nocheck(pool, page 0, order 0) => page 1 + * __find_buddy_nocheck(pool, page 0, order 1) => page 2 + * __find_buddy_nocheck(pool, page 1, order 0) => page 0 + * __find_buddy_nocheck(pool, page 2, order 0) => page 3 + */ +static struct hyp_page *__find_buddy_nocheck(struct hyp_pool *pool, + struct hyp_page *p, + unsigned short order) +{ + phys_addr_t addr = hyp_page_to_phys(p); + + addr ^= (PAGE_SIZE << order); + + /* + * Don't return a page outside the pool range -- it belongs to + * something else and may not be mapped in hyp_vmemmap. + */ + if (addr < pool->range_start || addr >= pool->range_end) + return NULL; + + return hyp_phys_to_page(addr); +} + +/* Find a buddy page currently available for allocation */ +static struct hyp_page *__find_buddy_avail(struct hyp_pool *pool, + struct hyp_page *p, + unsigned short order) +{ + struct hyp_page *buddy = __find_buddy_nocheck(pool, p, order); + + if (!buddy || buddy->order != order || buddy->refcount) + return NULL; + + return buddy; + +} + +/* + * Pages that are available for allocation are tracked in free-lists, so we use + * the pages themselves to store the list nodes to avoid wasting space. As the + * allocator always returns zeroed pages (which are zeroed on the hyp_put_page() + * path to optimize allocation speed), we also need to clean-up the list node in + * each page when we take it out of the list. + */ +static inline void page_remove_from_list(struct hyp_page *p) +{ + struct list_head *node = hyp_page_to_virt(p); + + __list_del_entry(node); + memset(node, 0, sizeof(*node)); +} + +static inline void page_add_to_list(struct hyp_page *p, struct list_head *head) +{ + struct list_head *node = hyp_page_to_virt(p); + + INIT_LIST_HEAD(node); + list_add_tail(node, head); +} + +static inline struct hyp_page *node_to_page(struct list_head *node) +{ + return hyp_virt_to_page(node); +} + +static void __hyp_attach_page(struct hyp_pool *pool, + struct hyp_page *p) +{ + phys_addr_t phys = hyp_page_to_phys(p); + unsigned short order = p->order; + struct hyp_page *buddy; + + memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order); + + /* Skip coalescing for 'external' pages being freed into the pool. */ + if (phys < pool->range_start || phys >= pool->range_end) + goto insert; + + /* + * Only the first struct hyp_page of a high-order page (otherwise known + * as the 'head') should have p->order set. The non-head pages should + * have p->order = HYP_NO_ORDER. Here @p may no longer be the head + * after coalescing, so make sure to mark it HYP_NO_ORDER proactively. + */ + p->order = HYP_NO_ORDER; + for (; (order + 1) <= pool->max_order; order++) { + buddy = __find_buddy_avail(pool, p, order); + if (!buddy) + break; + + /* Take the buddy out of its list, and coalesce with @p */ + page_remove_from_list(buddy); + buddy->order = HYP_NO_ORDER; + p = min(p, buddy); + } + +insert: + /* Mark the new head, and insert it */ + p->order = order; + page_add_to_list(p, &pool->free_area[order]); +} + +static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, + struct hyp_page *p, + unsigned short order) +{ + struct hyp_page *buddy; + + page_remove_from_list(p); + while (p->order > order) { + /* + * The buddy of order n - 1 currently has HYP_NO_ORDER as it + * is covered by a higher-level page (whose head is @p). Use + * __find_buddy_nocheck() to find it and inject it in the + * free_list[n - 1], effectively splitting @p in half. + */ + p->order--; + buddy = __find_buddy_nocheck(pool, p, p->order); + buddy->order = p->order; + page_add_to_list(buddy, &pool->free_area[buddy->order]); + } + + return p; +} + +static void __hyp_put_page(struct hyp_pool *pool, struct hyp_page *p) +{ + if (hyp_page_ref_dec_and_test(p)) + __hyp_attach_page(pool, p); +} + +/* + * Changes to the buddy tree and page refcounts must be done with the hyp_pool + * lock held. If a refcount change requires an update to the buddy tree (e.g. + * hyp_put_page()), both operations must be done within the same critical + * section to guarantee transient states (e.g. a page with null refcount but + * not yet attached to a free list) can't be observed by well-behaved readers. + */ +void hyp_put_page(struct hyp_pool *pool, void *addr) +{ + struct hyp_page *p = hyp_virt_to_page(addr); + + hyp_spin_lock(&pool->lock); + __hyp_put_page(pool, p); + hyp_spin_unlock(&pool->lock); +} + +void hyp_get_page(struct hyp_pool *pool, void *addr) +{ + struct hyp_page *p = hyp_virt_to_page(addr); + + hyp_spin_lock(&pool->lock); + hyp_page_ref_inc(p); + hyp_spin_unlock(&pool->lock); +} + +void hyp_split_page(struct hyp_page *p) +{ + unsigned short order = p->order; + unsigned int i; + + p->order = 0; + for (i = 1; i < (1 << order); i++) { + struct hyp_page *tail = p + i; + + tail->order = 0; + hyp_set_page_refcounted(tail); + } +} + +void *hyp_alloc_pages(struct hyp_pool *pool, unsigned short order) +{ + unsigned short i = order; + struct hyp_page *p; + + hyp_spin_lock(&pool->lock); + + /* Look for a high-enough-order page */ + while (i <= pool->max_order && list_empty(&pool->free_area[i])) + i++; + if (i > pool->max_order) { + hyp_spin_unlock(&pool->lock); + return NULL; + } + + /* Extract it from the tree at the right order */ + p = node_to_page(pool->free_area[i].next); + p = __hyp_extract_page(pool, p, order); + + hyp_set_page_refcounted(p); + hyp_spin_unlock(&pool->lock); + + return hyp_page_to_virt(p); +} + +int hyp_pool_init(struct hyp_pool *pool, u64 pfn, unsigned int nr_pages, + unsigned int reserved_pages) +{ + phys_addr_t phys = hyp_pfn_to_phys(pfn); + struct hyp_page *p; + int i; + + hyp_spin_lock_init(&pool->lock); + pool->max_order = min(MAX_PAGE_ORDER, + get_order(nr_pages << PAGE_SHIFT)); + for (i = 0; i <= pool->max_order; i++) + INIT_LIST_HEAD(&pool->free_area[i]); + pool->range_start = phys; + pool->range_end = phys + (nr_pages << PAGE_SHIFT); + + /* Init the vmemmap portion */ + p = hyp_phys_to_page(phys); + for (i = 0; i < nr_pages; i++) + hyp_set_page_refcounted(&p[i]); + + /* Attach the unused pages to the buddy tree */ + for (i = reserved_pages; i < nr_pages; i++) + __hyp_put_page(pool, &p[i]); + + return 0; +} diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c new file mode 100644 index 000000000000..26dd9a20ad6e --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -0,0 +1,640 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#include <linux/kvm_host.h> +#include <linux/mm.h> +#include <nvhe/fixed_config.h> +#include <nvhe/mem_protect.h> +#include <nvhe/memory.h> +#include <nvhe/pkvm.h> +#include <nvhe/trap_handler.h> + +/* Used by icache_is_aliasing(). */ +unsigned long __icache_flags; + +/* Used by kvm_get_vttbr(). */ +unsigned int kvm_arm_vmid_bits; + +/* + * Set trap register values based on features in ID_AA64PFR0. + */ +static void pvm_init_traps_aa64pfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR0_EL1); + u64 hcr_set = HCR_RW; + u64 hcr_clear = 0; + u64 cptr_set = 0; + u64 cptr_clear = 0; + + /* Protected KVM does not support AArch32 guests. */ + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL0), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_EL1_ELx_64BIT_ONLY); + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL1), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_EL1_ELx_64BIT_ONLY); + + /* + * Linux guests assume support for floating-point and Advanced SIMD. Do + * not change the trapping behavior for these from the KVM default. + */ + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_FP), + PVM_ID_AA64PFR0_ALLOW)); + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AdvSIMD), + PVM_ID_AA64PFR0_ALLOW)); + + if (has_hvhe()) + hcr_set |= HCR_E2H; + + /* Trap RAS unless all current versions are supported */ + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_RAS), feature_ids) < + ID_AA64PFR0_EL1_RAS_V1P1) { + hcr_set |= HCR_TERR | HCR_TEA; + hcr_clear |= HCR_FIEN; + } + + /* Trap AMU */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU), feature_ids)) { + hcr_clear |= HCR_AMVOFFEN; + cptr_set |= CPTR_EL2_TAM; + } + + /* Trap SVE */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE), feature_ids)) { + if (has_hvhe()) + cptr_clear |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN; + else + cptr_set |= CPTR_EL2_TZ; + } + + vcpu->arch.hcr_el2 |= hcr_set; + vcpu->arch.hcr_el2 &= ~hcr_clear; + vcpu->arch.cptr_el2 |= cptr_set; + vcpu->arch.cptr_el2 &= ~cptr_clear; +} + +/* + * Set trap register values based on features in ID_AA64PFR1. + */ +static void pvm_init_traps_aa64pfr1(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR1_EL1); + u64 hcr_set = 0; + u64 hcr_clear = 0; + + /* Memory Tagging: Trap and Treat as Untagged if not supported. */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE), feature_ids)) { + hcr_set |= HCR_TID5; + hcr_clear |= HCR_DCT | HCR_ATA; + } + + vcpu->arch.hcr_el2 |= hcr_set; + vcpu->arch.hcr_el2 &= ~hcr_clear; +} + +/* + * Set trap register values based on features in ID_AA64DFR0. + */ +static void pvm_init_traps_aa64dfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64DFR0_EL1); + u64 mdcr_set = 0; + u64 mdcr_clear = 0; + u64 cptr_set = 0; + + /* Trap/constrain PMU */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), feature_ids)) { + mdcr_set |= MDCR_EL2_TPM | MDCR_EL2_TPMCR; + mdcr_clear |= MDCR_EL2_HPME | MDCR_EL2_MTPME | + MDCR_EL2_HPMN_MASK; + } + + /* Trap Debug */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DebugVer), feature_ids)) + mdcr_set |= MDCR_EL2_TDRA | MDCR_EL2_TDA | MDCR_EL2_TDE; + + /* Trap OS Double Lock */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_DoubleLock), feature_ids)) + mdcr_set |= MDCR_EL2_TDOSA; + + /* Trap SPE */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer), feature_ids)) { + mdcr_set |= MDCR_EL2_TPMS; + mdcr_clear |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; + } + + /* Trap Trace Filter */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_TraceFilt), feature_ids)) + mdcr_set |= MDCR_EL2_TTRF; + + /* Trap Trace */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_TraceVer), feature_ids)) { + if (has_hvhe()) + cptr_set |= CPACR_EL1_TTA; + else + cptr_set |= CPTR_EL2_TTA; + } + + /* Trap External Trace */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_ExtTrcBuff), feature_ids)) + mdcr_clear |= MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT; + + vcpu->arch.mdcr_el2 |= mdcr_set; + vcpu->arch.mdcr_el2 &= ~mdcr_clear; + vcpu->arch.cptr_el2 |= cptr_set; +} + +/* + * Set trap register values based on features in ID_AA64MMFR0. + */ +static void pvm_init_traps_aa64mmfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR0_EL1); + u64 mdcr_set = 0; + + /* Trap Debug Communications Channel registers */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_FGT), feature_ids)) + mdcr_set |= MDCR_EL2_TDCC; + + vcpu->arch.mdcr_el2 |= mdcr_set; +} + +/* + * Set trap register values based on features in ID_AA64MMFR1. + */ +static void pvm_init_traps_aa64mmfr1(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR1_EL1); + u64 hcr_set = 0; + + /* Trap LOR */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_EL1_LO), feature_ids)) + hcr_set |= HCR_TLOR; + + vcpu->arch.hcr_el2 |= hcr_set; +} + +/* + * Set baseline trap register values. + */ +static void pvm_init_trap_regs(struct kvm_vcpu *vcpu) +{ + const u64 hcr_trap_feat_regs = HCR_TID3; + const u64 hcr_trap_impdef = HCR_TACR | HCR_TIDCP | HCR_TID1; + + /* + * Always trap: + * - Feature id registers: to control features exposed to guests + * - Implementation-defined features + */ + vcpu->arch.hcr_el2 |= hcr_trap_feat_regs | hcr_trap_impdef; + + /* Clear res0 and set res1 bits to trap potential new features. */ + vcpu->arch.hcr_el2 &= ~(HCR_RES0); + vcpu->arch.mdcr_el2 &= ~(MDCR_EL2_RES0); + if (!has_hvhe()) { + vcpu->arch.cptr_el2 |= CPTR_NVHE_EL2_RES1; + vcpu->arch.cptr_el2 &= ~(CPTR_NVHE_EL2_RES0); + } +} + +/* + * Initialize trap register values for protected VMs. + */ +void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu) +{ + pvm_init_trap_regs(vcpu); + pvm_init_traps_aa64pfr0(vcpu); + pvm_init_traps_aa64pfr1(vcpu); + pvm_init_traps_aa64dfr0(vcpu); + pvm_init_traps_aa64mmfr0(vcpu); + pvm_init_traps_aa64mmfr1(vcpu); +} + +/* + * Start the VM table handle at the offset defined instead of at 0. + * Mainly for sanity checking and debugging. + */ +#define HANDLE_OFFSET 0x1000 + +static unsigned int vm_handle_to_idx(pkvm_handle_t handle) +{ + return handle - HANDLE_OFFSET; +} + +static pkvm_handle_t idx_to_vm_handle(unsigned int idx) +{ + return idx + HANDLE_OFFSET; +} + +/* + * Spinlock for protecting state related to the VM table. Protects writes + * to 'vm_table' and 'nr_table_entries' as well as reads and writes to + * 'last_hyp_vcpu_lookup'. + */ +static DEFINE_HYP_SPINLOCK(vm_table_lock); + +/* + * The table of VM entries for protected VMs in hyp. + * Allocated at hyp initialization and setup. + */ +static struct pkvm_hyp_vm **vm_table; + +void pkvm_hyp_vm_table_init(void *tbl) +{ + WARN_ON(vm_table); + vm_table = tbl; +} + +/* + * Return the hyp vm structure corresponding to the handle. + */ +static struct pkvm_hyp_vm *get_vm_by_handle(pkvm_handle_t handle) +{ + unsigned int idx = vm_handle_to_idx(handle); + + if (unlikely(idx >= KVM_MAX_PVMS)) + return NULL; + + return vm_table[idx]; +} + +struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle, + unsigned int vcpu_idx) +{ + struct pkvm_hyp_vcpu *hyp_vcpu = NULL; + struct pkvm_hyp_vm *hyp_vm; + + hyp_spin_lock(&vm_table_lock); + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm || hyp_vm->nr_vcpus <= vcpu_idx) + goto unlock; + + hyp_vcpu = hyp_vm->vcpus[vcpu_idx]; + hyp_page_ref_inc(hyp_virt_to_page(hyp_vm)); +unlock: + hyp_spin_unlock(&vm_table_lock); + return hyp_vcpu; +} + +void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct pkvm_hyp_vm *hyp_vm = pkvm_hyp_vcpu_to_hyp_vm(hyp_vcpu); + + hyp_spin_lock(&vm_table_lock); + hyp_page_ref_dec(hyp_virt_to_page(hyp_vm)); + hyp_spin_unlock(&vm_table_lock); +} + +static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu) +{ + if (host_vcpu) + hyp_unpin_shared_mem(host_vcpu, host_vcpu + 1); +} + +static void unpin_host_vcpus(struct pkvm_hyp_vcpu *hyp_vcpus[], + unsigned int nr_vcpus) +{ + int i; + + for (i = 0; i < nr_vcpus; i++) + unpin_host_vcpu(hyp_vcpus[i]->host_vcpu); +} + +static void init_pkvm_hyp_vm(struct kvm *host_kvm, struct pkvm_hyp_vm *hyp_vm, + unsigned int nr_vcpus) +{ + hyp_vm->host_kvm = host_kvm; + hyp_vm->kvm.created_vcpus = nr_vcpus; + hyp_vm->kvm.arch.mmu.vtcr = host_mmu.arch.mmu.vtcr; +} + +static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, + struct pkvm_hyp_vm *hyp_vm, + struct kvm_vcpu *host_vcpu, + unsigned int vcpu_idx) +{ + int ret = 0; + + if (hyp_pin_shared_mem(host_vcpu, host_vcpu + 1)) + return -EBUSY; + + if (host_vcpu->vcpu_idx != vcpu_idx) { + ret = -EINVAL; + goto done; + } + + hyp_vcpu->host_vcpu = host_vcpu; + + hyp_vcpu->vcpu.kvm = &hyp_vm->kvm; + hyp_vcpu->vcpu.vcpu_id = READ_ONCE(host_vcpu->vcpu_id); + hyp_vcpu->vcpu.vcpu_idx = vcpu_idx; + + hyp_vcpu->vcpu.arch.hw_mmu = &hyp_vm->kvm.arch.mmu; + hyp_vcpu->vcpu.arch.cflags = READ_ONCE(host_vcpu->arch.cflags); +done: + if (ret) + unpin_host_vcpu(host_vcpu); + return ret; +} + +static int find_free_vm_table_entry(struct kvm *host_kvm) +{ + int i; + + for (i = 0; i < KVM_MAX_PVMS; ++i) { + if (!vm_table[i]) + return i; + } + + return -ENOMEM; +} + +/* + * Allocate a VM table entry and insert a pointer to the new vm. + * + * Return a unique handle to the protected VM on success, + * negative error code on failure. + */ +static pkvm_handle_t insert_vm_table_entry(struct kvm *host_kvm, + struct pkvm_hyp_vm *hyp_vm) +{ + struct kvm_s2_mmu *mmu = &hyp_vm->kvm.arch.mmu; + int idx; + + hyp_assert_lock_held(&vm_table_lock); + + /* + * Initializing protected state might have failed, yet a malicious + * host could trigger this function. Thus, ensure that 'vm_table' + * exists. + */ + if (unlikely(!vm_table)) + return -EINVAL; + + idx = find_free_vm_table_entry(host_kvm); + if (idx < 0) + return idx; + + hyp_vm->kvm.arch.pkvm.handle = idx_to_vm_handle(idx); + + /* VMID 0 is reserved for the host */ + atomic64_set(&mmu->vmid.id, idx + 1); + + mmu->arch = &hyp_vm->kvm.arch; + mmu->pgt = &hyp_vm->pgt; + + vm_table[idx] = hyp_vm; + return hyp_vm->kvm.arch.pkvm.handle; +} + +/* + * Deallocate and remove the VM table entry corresponding to the handle. + */ +static void remove_vm_table_entry(pkvm_handle_t handle) +{ + hyp_assert_lock_held(&vm_table_lock); + vm_table[vm_handle_to_idx(handle)] = NULL; +} + +static size_t pkvm_get_hyp_vm_size(unsigned int nr_vcpus) +{ + return size_add(sizeof(struct pkvm_hyp_vm), + size_mul(sizeof(struct pkvm_hyp_vcpu *), nr_vcpus)); +} + +static void *map_donated_memory_noclear(unsigned long host_va, size_t size) +{ + void *va = (void *)kern_hyp_va(host_va); + + if (!PAGE_ALIGNED(va)) + return NULL; + + if (__pkvm_host_donate_hyp(hyp_virt_to_pfn(va), + PAGE_ALIGN(size) >> PAGE_SHIFT)) + return NULL; + + return va; +} + +static void *map_donated_memory(unsigned long host_va, size_t size) +{ + void *va = map_donated_memory_noclear(host_va, size); + + if (va) + memset(va, 0, size); + + return va; +} + +static void __unmap_donated_memory(void *va, size_t size) +{ + WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(va), + PAGE_ALIGN(size) >> PAGE_SHIFT)); +} + +static void unmap_donated_memory(void *va, size_t size) +{ + if (!va) + return; + + memset(va, 0, size); + __unmap_donated_memory(va, size); +} + +static void unmap_donated_memory_noclear(void *va, size_t size) +{ + if (!va) + return; + + __unmap_donated_memory(va, size); +} + +/* + * Initialize the hypervisor copy of the protected VM state using the + * memory donated by the host. + * + * Unmaps the donated memory from the host at stage 2. + * + * host_kvm: A pointer to the host's struct kvm. + * vm_hva: The host va of the area being donated for the VM state. + * Must be page aligned. + * pgd_hva: The host va of the area being donated for the stage-2 PGD for + * the VM. Must be page aligned. Its size is implied by the VM's + * VTCR. + * + * Return a unique handle to the protected VM on success, + * negative error code on failure. + */ +int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva, + unsigned long pgd_hva) +{ + struct pkvm_hyp_vm *hyp_vm = NULL; + size_t vm_size, pgd_size; + unsigned int nr_vcpus; + void *pgd = NULL; + int ret; + + ret = hyp_pin_shared_mem(host_kvm, host_kvm + 1); + if (ret) + return ret; + + nr_vcpus = READ_ONCE(host_kvm->created_vcpus); + if (nr_vcpus < 1) { + ret = -EINVAL; + goto err_unpin_kvm; + } + + vm_size = pkvm_get_hyp_vm_size(nr_vcpus); + pgd_size = kvm_pgtable_stage2_pgd_size(host_mmu.arch.mmu.vtcr); + + ret = -ENOMEM; + + hyp_vm = map_donated_memory(vm_hva, vm_size); + if (!hyp_vm) + goto err_remove_mappings; + + pgd = map_donated_memory_noclear(pgd_hva, pgd_size); + if (!pgd) + goto err_remove_mappings; + + init_pkvm_hyp_vm(host_kvm, hyp_vm, nr_vcpus); + + hyp_spin_lock(&vm_table_lock); + ret = insert_vm_table_entry(host_kvm, hyp_vm); + if (ret < 0) + goto err_unlock; + + ret = kvm_guest_prepare_stage2(hyp_vm, pgd); + if (ret) + goto err_remove_vm_table_entry; + hyp_spin_unlock(&vm_table_lock); + + return hyp_vm->kvm.arch.pkvm.handle; + +err_remove_vm_table_entry: + remove_vm_table_entry(hyp_vm->kvm.arch.pkvm.handle); +err_unlock: + hyp_spin_unlock(&vm_table_lock); +err_remove_mappings: + unmap_donated_memory(hyp_vm, vm_size); + unmap_donated_memory(pgd, pgd_size); +err_unpin_kvm: + hyp_unpin_shared_mem(host_kvm, host_kvm + 1); + return ret; +} + +/* + * Initialize the hypervisor copy of the protected vCPU state using the + * memory donated by the host. + * + * handle: The handle for the protected vm. + * host_vcpu: A pointer to the corresponding host vcpu. + * vcpu_hva: The host va of the area being donated for the vcpu state. + * Must be page aligned. The size of the area must be equal to + * the page-aligned size of 'struct pkvm_hyp_vcpu'. + * Return 0 on success, negative error code on failure. + */ +int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu, + unsigned long vcpu_hva) +{ + struct pkvm_hyp_vcpu *hyp_vcpu; + struct pkvm_hyp_vm *hyp_vm; + unsigned int idx; + int ret; + + hyp_vcpu = map_donated_memory(vcpu_hva, sizeof(*hyp_vcpu)); + if (!hyp_vcpu) + return -ENOMEM; + + hyp_spin_lock(&vm_table_lock); + + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm) { + ret = -ENOENT; + goto unlock; + } + + idx = hyp_vm->nr_vcpus; + if (idx >= hyp_vm->kvm.created_vcpus) { + ret = -EINVAL; + goto unlock; + } + + ret = init_pkvm_hyp_vcpu(hyp_vcpu, hyp_vm, host_vcpu, idx); + if (ret) + goto unlock; + + hyp_vm->vcpus[idx] = hyp_vcpu; + hyp_vm->nr_vcpus++; +unlock: + hyp_spin_unlock(&vm_table_lock); + + if (ret) + unmap_donated_memory(hyp_vcpu, sizeof(*hyp_vcpu)); + + return ret; +} + +static void +teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size) +{ + size = PAGE_ALIGN(size); + memset(addr, 0, size); + + for (void *start = addr; start < addr + size; start += PAGE_SIZE) + push_hyp_memcache(mc, start, hyp_virt_to_phys); + + unmap_donated_memory_noclear(addr, size); +} + +int __pkvm_teardown_vm(pkvm_handle_t handle) +{ + struct kvm_hyp_memcache *mc; + struct pkvm_hyp_vm *hyp_vm; + struct kvm *host_kvm; + unsigned int idx; + size_t vm_size; + int err; + + hyp_spin_lock(&vm_table_lock); + hyp_vm = get_vm_by_handle(handle); + if (!hyp_vm) { + err = -ENOENT; + goto err_unlock; + } + + if (WARN_ON(hyp_page_count(hyp_vm))) { + err = -EBUSY; + goto err_unlock; + } + + host_kvm = hyp_vm->host_kvm; + + /* Ensure the VMID is clean before it can be reallocated */ + __kvm_tlb_flush_vmid(&hyp_vm->kvm.arch.mmu); + remove_vm_table_entry(handle); + hyp_spin_unlock(&vm_table_lock); + + /* Reclaim guest pages (including page-table pages) */ + mc = &host_kvm->arch.pkvm.teardown_mc; + reclaim_guest_pages(hyp_vm, mc); + unpin_host_vcpus(hyp_vm->vcpus, hyp_vm->nr_vcpus); + + /* Push the metadata pages to the teardown memcache */ + for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) { + struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx]; + + teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu)); + } + + vm_size = pkvm_get_hyp_vm_size(hyp_vm->kvm.created_vcpus); + teardown_donated_memory(mc, hyp_vm, vm_size); + hyp_unpin_shared_mem(host_kvm, host_kvm + 1); + return 0; + +err_unlock: + hyp_spin_unlock(&vm_table_lock); + return err; +} diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c new file mode 100644 index 000000000000..d57bcb6ab94d --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c @@ -0,0 +1,303 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 - Google LLC + * Author: David Brazdil <dbrazdil@google.com> + */ + +#include <asm/kvm_asm.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <linux/arm-smccc.h> +#include <linux/kvm_host.h> +#include <uapi/linux/psci.h> + +#include <nvhe/memory.h> +#include <nvhe/trap_handler.h> + +void kvm_hyp_cpu_entry(unsigned long r0); +void kvm_hyp_cpu_resume(unsigned long r0); + +void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); + +/* Config options set by the host. */ +struct kvm_host_psci_config __ro_after_init kvm_host_psci_config; + +#define INVALID_CPU_ID UINT_MAX + +struct psci_boot_args { + atomic_t lock; + unsigned long pc; + unsigned long r0; +}; + +#define PSCI_BOOT_ARGS_UNLOCKED 0 +#define PSCI_BOOT_ARGS_LOCKED 1 + +#define PSCI_BOOT_ARGS_INIT \ + ((struct psci_boot_args){ \ + .lock = ATOMIC_INIT(PSCI_BOOT_ARGS_UNLOCKED), \ + }) + +static DEFINE_PER_CPU(struct psci_boot_args, cpu_on_args) = PSCI_BOOT_ARGS_INIT; +static DEFINE_PER_CPU(struct psci_boot_args, suspend_args) = PSCI_BOOT_ARGS_INIT; + +#define is_psci_0_1(what, func_id) \ + (kvm_host_psci_config.psci_0_1_ ## what ## _implemented && \ + (func_id) == kvm_host_psci_config.function_ids_0_1.what) + +static bool is_psci_0_1_call(u64 func_id) +{ + return (is_psci_0_1(cpu_suspend, func_id) || + is_psci_0_1(cpu_on, func_id) || + is_psci_0_1(cpu_off, func_id) || + is_psci_0_1(migrate, func_id)); +} + +static bool is_psci_0_2_call(u64 func_id) +{ + /* SMCCC reserves IDs 0x00-1F with the given 32/64-bit base for PSCI. */ + return (PSCI_0_2_FN(0) <= func_id && func_id <= PSCI_0_2_FN(31)) || + (PSCI_0_2_FN64(0) <= func_id && func_id <= PSCI_0_2_FN64(31)); +} + +static unsigned long psci_call(unsigned long fn, unsigned long arg0, + unsigned long arg1, unsigned long arg2) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(fn, arg0, arg1, arg2, &res); + return res.a0; +} + +static unsigned long psci_forward(struct kvm_cpu_context *host_ctxt) +{ + return psci_call(cpu_reg(host_ctxt, 0), cpu_reg(host_ctxt, 1), + cpu_reg(host_ctxt, 2), cpu_reg(host_ctxt, 3)); +} + +static unsigned int find_cpu_id(u64 mpidr) +{ + unsigned int i; + + /* Reject invalid MPIDRs */ + if (mpidr & ~MPIDR_HWID_BITMASK) + return INVALID_CPU_ID; + + for (i = 0; i < NR_CPUS; i++) { + if (cpu_logical_map(i) == mpidr) + return i; + } + + return INVALID_CPU_ID; +} + +static __always_inline bool try_acquire_boot_args(struct psci_boot_args *args) +{ + return atomic_cmpxchg_acquire(&args->lock, + PSCI_BOOT_ARGS_UNLOCKED, + PSCI_BOOT_ARGS_LOCKED) == + PSCI_BOOT_ARGS_UNLOCKED; +} + +static __always_inline void release_boot_args(struct psci_boot_args *args) +{ + atomic_set_release(&args->lock, PSCI_BOOT_ARGS_UNLOCKED); +} + +static int psci_cpu_on(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, mpidr, host_ctxt, 1); + DECLARE_REG(unsigned long, pc, host_ctxt, 2); + DECLARE_REG(unsigned long, r0, host_ctxt, 3); + + unsigned int cpu_id; + struct psci_boot_args *boot_args; + struct kvm_nvhe_init_params *init_params; + int ret; + + /* + * Find the logical CPU ID for the given MPIDR. The search set is + * the set of CPUs that were online at the point of KVM initialization. + * Booting other CPUs is rejected because their cpufeatures were not + * checked against the finalized capabilities. This could be relaxed + * by doing the feature checks in hyp. + */ + cpu_id = find_cpu_id(mpidr); + if (cpu_id == INVALID_CPU_ID) + return PSCI_RET_INVALID_PARAMS; + + boot_args = per_cpu_ptr(&cpu_on_args, cpu_id); + init_params = per_cpu_ptr(&kvm_init_params, cpu_id); + + /* Check if the target CPU is already being booted. */ + if (!try_acquire_boot_args(boot_args)) + return PSCI_RET_ALREADY_ON; + + boot_args->pc = pc; + boot_args->r0 = r0; + wmb(); + + ret = psci_call(func_id, mpidr, + __hyp_pa(&kvm_hyp_cpu_entry), + __hyp_pa(init_params)); + + /* If successful, the lock will be released by the target CPU. */ + if (ret != PSCI_RET_SUCCESS) + release_boot_args(boot_args); + + return ret; +} + +static int psci_cpu_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, power_state, host_ctxt, 1); + DECLARE_REG(unsigned long, pc, host_ctxt, 2); + DECLARE_REG(unsigned long, r0, host_ctxt, 3); + + struct psci_boot_args *boot_args; + struct kvm_nvhe_init_params *init_params; + + boot_args = this_cpu_ptr(&suspend_args); + init_params = this_cpu_ptr(&kvm_init_params); + + /* + * No need to acquire a lock before writing to boot_args because a core + * can only suspend itself. Racy CPU_ON calls use a separate struct. + */ + boot_args->pc = pc; + boot_args->r0 = r0; + + /* + * Will either return if shallow sleep state, or wake up into the entry + * point if it is a deep sleep state. + */ + return psci_call(func_id, power_state, + __hyp_pa(&kvm_hyp_cpu_resume), + __hyp_pa(init_params)); +} + +static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(unsigned long, pc, host_ctxt, 1); + DECLARE_REG(unsigned long, r0, host_ctxt, 2); + + struct psci_boot_args *boot_args; + struct kvm_nvhe_init_params *init_params; + + boot_args = this_cpu_ptr(&suspend_args); + init_params = this_cpu_ptr(&kvm_init_params); + + /* + * No need to acquire a lock before writing to boot_args because a core + * can only suspend itself. Racy CPU_ON calls use a separate struct. + */ + boot_args->pc = pc; + boot_args->r0 = r0; + + /* Will only return on error. */ + return psci_call(func_id, + __hyp_pa(&kvm_hyp_cpu_resume), + __hyp_pa(init_params), 0); +} + +asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on) +{ + struct psci_boot_args *boot_args; + struct kvm_cpu_context *host_ctxt; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + + if (is_cpu_on) + boot_args = this_cpu_ptr(&cpu_on_args); + else + boot_args = this_cpu_ptr(&suspend_args); + + cpu_reg(host_ctxt, 0) = boot_args->r0; + write_sysreg_el2(boot_args->pc, SYS_ELR); + + if (is_cpu_on) + release_boot_args(boot_args); + + __host_enter(host_ctxt); +} + +static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + if (is_psci_0_1(cpu_off, func_id) || is_psci_0_1(migrate, func_id)) + return psci_forward(host_ctxt); + if (is_psci_0_1(cpu_on, func_id)) + return psci_cpu_on(func_id, host_ctxt); + if (is_psci_0_1(cpu_suspend, func_id)) + return psci_cpu_suspend(func_id, host_ctxt); + + return PSCI_RET_NOT_SUPPORTED; +} + +static unsigned long psci_0_2_handler(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + switch (func_id) { + case PSCI_0_2_FN_PSCI_VERSION: + case PSCI_0_2_FN_CPU_OFF: + case PSCI_0_2_FN64_AFFINITY_INFO: + case PSCI_0_2_FN64_MIGRATE: + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: + return psci_forward(host_ctxt); + /* + * SYSTEM_OFF/RESET should not return according to the spec. + * Allow it so as to stay robust to broken firmware. + */ + case PSCI_0_2_FN_SYSTEM_OFF: + case PSCI_0_2_FN_SYSTEM_RESET: + return psci_forward(host_ctxt); + case PSCI_0_2_FN64_CPU_SUSPEND: + return psci_cpu_suspend(func_id, host_ctxt); + case PSCI_0_2_FN64_CPU_ON: + return psci_cpu_on(func_id, host_ctxt); + default: + return PSCI_RET_NOT_SUPPORTED; + } +} + +static unsigned long psci_1_0_handler(u64 func_id, struct kvm_cpu_context *host_ctxt) +{ + switch (func_id) { + case PSCI_1_0_FN_PSCI_FEATURES: + case PSCI_1_0_FN_SET_SUSPEND_MODE: + case PSCI_1_1_FN64_SYSTEM_RESET2: + return psci_forward(host_ctxt); + case PSCI_1_0_FN64_SYSTEM_SUSPEND: + return psci_system_suspend(func_id, host_ctxt); + default: + return psci_0_2_handler(func_id, host_ctxt); + } +} + +bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt, u32 func_id) +{ + unsigned long ret; + + switch (kvm_host_psci_config.version) { + case PSCI_VERSION(0, 1): + if (!is_psci_0_1_call(func_id)) + return false; + ret = psci_0_1_handler(func_id, host_ctxt); + break; + case PSCI_VERSION(0, 2): + if (!is_psci_0_2_call(func_id)) + return false; + ret = psci_0_2_handler(func_id, host_ctxt); + break; + default: + if (!is_psci_0_2_call(func_id)) + return false; + ret = psci_1_0_handler(func_id, host_ctxt); + break; + } + + cpu_reg(host_ctxt, 0) = ret; + cpu_reg(host_ctxt, 1) = 0; + cpu_reg(host_ctxt, 2) = 0; + cpu_reg(host_ctxt, 3) = 0; + return true; +} diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c new file mode 100644 index 000000000000..bc58d1b515af --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -0,0 +1,346 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> + +#include <nvhe/early_alloc.h> +#include <nvhe/ffa.h> +#include <nvhe/fixed_config.h> +#include <nvhe/gfp.h> +#include <nvhe/memory.h> +#include <nvhe/mem_protect.h> +#include <nvhe/mm.h> +#include <nvhe/pkvm.h> +#include <nvhe/trap_handler.h> + +unsigned long hyp_nr_cpus; + +#define hyp_percpu_size ((unsigned long)__per_cpu_end - \ + (unsigned long)__per_cpu_start) + +static void *vmemmap_base; +static void *vm_table_base; +static void *hyp_pgt_base; +static void *host_s2_pgt_base; +static void *ffa_proxy_pages; +static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; +static struct hyp_pool hpool; + +static int divide_memory_pool(void *virt, unsigned long size) +{ + unsigned long nr_pages; + + hyp_early_alloc_init(virt, size); + + nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); + vmemmap_base = hyp_early_alloc_contig(nr_pages); + if (!vmemmap_base) + return -ENOMEM; + + nr_pages = hyp_vm_table_pages(); + vm_table_base = hyp_early_alloc_contig(nr_pages); + if (!vm_table_base) + return -ENOMEM; + + nr_pages = hyp_s1_pgtable_pages(); + hyp_pgt_base = hyp_early_alloc_contig(nr_pages); + if (!hyp_pgt_base) + return -ENOMEM; + + nr_pages = host_s2_pgtable_pages(); + host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); + if (!host_s2_pgt_base) + return -ENOMEM; + + nr_pages = hyp_ffa_proxy_pages(); + ffa_proxy_pages = hyp_early_alloc_contig(nr_pages); + if (!ffa_proxy_pages) + return -ENOMEM; + + return 0; +} + +static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, + unsigned long *per_cpu_base, + u32 hyp_va_bits) +{ + void *start, *end, *virt = hyp_phys_to_virt(phys); + unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; + enum kvm_pgtable_prot prot; + int ret, i; + + /* Recreate the hyp page-table using the early page allocator */ + hyp_early_alloc_init(hyp_pgt_base, pgt_size); + ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, + &hyp_early_alloc_mm_ops); + if (ret) + return ret; + + ret = hyp_create_idmap(hyp_va_bits); + if (ret) + return ret; + + ret = hyp_map_vectors(); + if (ret) + return ret; + + ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); + if (ret) + return ret; + + ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); + if (ret) + return ret; + + for (i = 0; i < hyp_nr_cpus; i++) { + struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i); + + start = (void *)kern_hyp_va(per_cpu_base[i]); + end = start + PAGE_ALIGN(hyp_percpu_size); + ret = pkvm_create_mappings(start, end, PAGE_HYP); + if (ret) + return ret; + + ret = pkvm_create_stack(params->stack_pa, ¶ms->stack_hyp_va); + if (ret) + return ret; + } + + /* + * Map the host sections RO in the hypervisor, but transfer the + * ownership from the host to the hypervisor itself to make sure they + * can't be donated or shared with another entity. + * + * The ownership transition requires matching changes in the host + * stage-2. This will be done later (see finalize_host_mappings()) once + * the hyp_vmemmap is addressable. + */ + prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); + ret = pkvm_create_mappings(&kvm_vgic_global_state, + &kvm_vgic_global_state + 1, prot); + if (ret) + return ret; + + return 0; +} + +static void update_nvhe_init_params(void) +{ + struct kvm_nvhe_init_params *params; + unsigned long i; + + for (i = 0; i < hyp_nr_cpus; i++) { + params = per_cpu_ptr(&kvm_init_params, i); + params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); + dcache_clean_inval_poc((unsigned long)params, + (unsigned long)params + sizeof(*params)); + } +} + +static void *hyp_zalloc_hyp_page(void *arg) +{ + return hyp_alloc_pages(&hpool, 0); +} + +static void hpool_get_page(void *addr) +{ + hyp_get_page(&hpool, addr); +} + +static void hpool_put_page(void *addr) +{ + hyp_put_page(&hpool, addr); +} + +static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + enum kvm_pgtable_prot prot; + enum pkvm_page_state state; + phys_addr_t phys; + + if (!kvm_pte_valid(ctx->old)) + return 0; + + if (ctx->level != KVM_PGTABLE_LAST_LEVEL) + return -EINVAL; + + phys = kvm_pte_to_phys(ctx->old); + if (!addr_is_memory(phys)) + return -EINVAL; + + /* + * Adjust the host stage-2 mappings to match the ownership attributes + * configured in the hypervisor stage-1. + */ + state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(ctx->old)); + switch (state) { + case PKVM_PAGE_OWNED: + return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); + case PKVM_PAGE_SHARED_OWNED: + prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); + break; + case PKVM_PAGE_SHARED_BORROWED: + prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); + break; + default: + return -EINVAL; + } + + return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); +} + +static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + /* + * Fix-up the refcount for the page-table pages as the early allocator + * was unable to access the hyp_vmemmap and so the buddy allocator has + * initialised the refcount to '1'. + */ + if (kvm_pte_valid(ctx->old)) + ctx->mm_ops->get_page(ctx->ptep); + + return 0; +} + +static int fix_host_ownership(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_host_ownership_walker, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + int i, ret; + + for (i = 0; i < hyp_memblock_nr; i++) { + struct memblock_region *reg = &hyp_memory[i]; + u64 start = (u64)hyp_phys_to_virt(reg->base); + + ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); + if (ret) + return ret; + } + + return 0; +} + +static int fix_hyp_pgtable_refcnt(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_hyp_pgtable_refcnt_walker, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + .arg = pkvm_pgtable.mm_ops, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), + &walker); +} + +void __noreturn __pkvm_init_finalise(void) +{ + struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); + struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; + unsigned long nr_pages, reserved_pages, pfn; + int ret; + + /* Now that the vmemmap is backed, install the full-fledged allocator */ + pfn = hyp_virt_to_pfn(hyp_pgt_base); + nr_pages = hyp_s1_pgtable_pages(); + reserved_pages = hyp_early_alloc_nr_used_pages(); + ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); + if (ret) + goto out; + + ret = kvm_host_prepare_stage2(host_s2_pgt_base); + if (ret) + goto out; + + pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_page = hyp_zalloc_hyp_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .get_page = hpool_get_page, + .put_page = hpool_put_page, + .page_count = hyp_page_count, + }; + pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; + + ret = fix_host_ownership(); + if (ret) + goto out; + + ret = fix_hyp_pgtable_refcnt(); + if (ret) + goto out; + + ret = hyp_create_pcpu_fixmap(); + if (ret) + goto out; + + ret = hyp_ffa_init(ffa_proxy_pages); + if (ret) + goto out; + + pkvm_hyp_vm_table_init(vm_table_base); +out: + /* + * We tail-called to here from handle___pkvm_init() and will not return, + * so make sure to propagate the return value to the host. + */ + cpu_reg(host_ctxt, 1) = ret; + + __host_enter(host_ctxt); +} + +int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, + unsigned long *per_cpu_base, u32 hyp_va_bits) +{ + struct kvm_nvhe_init_params *params; + void *virt = hyp_phys_to_virt(phys); + void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); + int ret; + + BUG_ON(kvm_check_pvm_sysreg_table()); + + if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) + return -EINVAL; + + hyp_spin_lock_init(&pkvm_pgd_lock); + hyp_nr_cpus = nr_cpus; + + ret = divide_memory_pool(virt, size); + if (ret) + return ret; + + ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); + if (ret) + return ret; + + update_nvhe_init_params(); + + /* Jump in the idmap page to switch to the new page-tables */ + params = this_cpu_ptr(&kvm_init_params); + fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); + fn(__hyp_pa(params), __pkvm_init_finalise); + + unreachable(); +} diff --git a/arch/arm64/kvm/hyp/nvhe/stacktrace.c b/arch/arm64/kvm/hyp/nvhe/stacktrace.c new file mode 100644 index 000000000000..ed6b58b19cfa --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/stacktrace.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * KVM nVHE hypervisor stack tracing support. + * + * Copyright (C) 2022 Google LLC + */ +#include <asm/kvm_asm.h> +#include <asm/kvm_hyp.h> +#include <asm/memory.h> +#include <asm/percpu.h> + +DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack) + __aligned(16); + +DEFINE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info); + +/* + * hyp_prepare_backtrace - Prepare non-protected nVHE backtrace. + * + * @fp : frame pointer at which to start the unwinding. + * @pc : program counter at which to start the unwinding. + * + * Save the information needed by the host to unwind the non-protected + * nVHE hypervisor stack in EL1. + */ +static void hyp_prepare_backtrace(unsigned long fp, unsigned long pc) +{ + struct kvm_nvhe_stacktrace_info *stacktrace_info = this_cpu_ptr(&kvm_stacktrace_info); + struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); + + stacktrace_info->stack_base = (unsigned long)(params->stack_hyp_va - PAGE_SIZE); + stacktrace_info->overflow_stack_base = (unsigned long)this_cpu_ptr(overflow_stack); + stacktrace_info->fp = fp; + stacktrace_info->pc = pc; +} + +#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE +#include <asm/stacktrace/nvhe.h> + +DEFINE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)], pkvm_stacktrace); + +static struct stack_info stackinfo_get_overflow(void) +{ + unsigned long low = (unsigned long)this_cpu_ptr(overflow_stack); + unsigned long high = low + OVERFLOW_STACK_SIZE; + + return (struct stack_info) { + .low = low, + .high = high, + }; +} + +static struct stack_info stackinfo_get_hyp(void) +{ + struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); + unsigned long high = params->stack_hyp_va; + unsigned long low = high - PAGE_SIZE; + + return (struct stack_info) { + .low = low, + .high = high, + }; +} + +static int unwind_next(struct unwind_state *state) +{ + return unwind_next_frame_record(state); +} + +static void notrace unwind(struct unwind_state *state, + stack_trace_consume_fn consume_entry, + void *cookie) +{ + while (1) { + int ret; + + if (!consume_entry(cookie, state->pc)) + break; + ret = unwind_next(state); + if (ret < 0) + break; + } +} + +/* + * pkvm_save_backtrace_entry - Saves a protected nVHE HYP stacktrace entry + * + * @arg : index of the entry in the stacktrace buffer + * @where : the program counter corresponding to the stack frame + * + * Save the return address of a stack frame to the shared stacktrace buffer. + * The host can access this shared buffer from EL1 to dump the backtrace. + */ +static bool pkvm_save_backtrace_entry(void *arg, unsigned long where) +{ + unsigned long *stacktrace = this_cpu_ptr(pkvm_stacktrace); + int *idx = (int *)arg; + + /* + * Need 2 free slots: 1 for current entry and 1 for the + * delimiter. + */ + if (*idx > ARRAY_SIZE(pkvm_stacktrace) - 2) + return false; + + stacktrace[*idx] = where; + stacktrace[++*idx] = 0UL; + + return true; +} + +/* + * pkvm_save_backtrace - Saves the protected nVHE HYP stacktrace + * + * @fp : frame pointer at which to start the unwinding. + * @pc : program counter at which to start the unwinding. + * + * Save the unwinded stack addresses to the shared stacktrace buffer. + * The host can access this shared buffer from EL1 to dump the backtrace. + */ +static void pkvm_save_backtrace(unsigned long fp, unsigned long pc) +{ + struct stack_info stacks[] = { + stackinfo_get_overflow(), + stackinfo_get_hyp(), + }; + struct unwind_state state = { + .stacks = stacks, + .nr_stacks = ARRAY_SIZE(stacks), + }; + int idx = 0; + + kvm_nvhe_unwind_init(&state, fp, pc); + + unwind(&state, pkvm_save_backtrace_entry, &idx); +} +#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */ +static void pkvm_save_backtrace(unsigned long fp, unsigned long pc) +{ +} +#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ + +/* + * kvm_nvhe_prepare_backtrace - prepare to dump the nVHE backtrace + * + * @fp : frame pointer at which to start the unwinding. + * @pc : program counter at which to start the unwinding. + * + * Saves the information needed by the host to dump the nVHE hypervisor + * backtrace. + */ +void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc) +{ + if (is_protected_kvm_enabled()) + pkvm_save_backtrace(fp, pc); + else + hyp_prepare_backtrace(fp, pc); +} diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c new file mode 100644 index 000000000000..c50f8459e4fc --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -0,0 +1,396 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/switch.h> +#include <hyp/sysreg-sr.h> + +#include <linux/arm-smccc.h> +#include <linux/kvm_host.h> +#include <linux/types.h> +#include <linux/jump_label.h> +#include <uapi/linux/psci.h> + +#include <kvm/arm_psci.h> + +#include <asm/barrier.h> +#include <asm/cpufeature.h> +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/fpsimd.h> +#include <asm/debug-monitors.h> +#include <asm/processor.h> + +#include <nvhe/fixed_config.h> +#include <nvhe/mem_protect.h> + +/* Non-VHE specific context */ +DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); +DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); +DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); + +extern void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc); + +static void __activate_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + ___activate_traps(vcpu); + __activate_traps_common(vcpu); + + val = vcpu->arch.cptr_el2; + val |= CPTR_EL2_TAM; /* Same bit irrespective of E2H */ + val |= has_hvhe() ? CPACR_EL1_TTA : CPTR_EL2_TTA; + if (cpus_have_final_cap(ARM64_SME)) { + if (has_hvhe()) + val &= ~(CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN); + else + val |= CPTR_EL2_TSM; + } + + if (!guest_owns_fp_regs(vcpu)) { + if (has_hvhe()) + val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN | + CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN); + else + val |= CPTR_EL2_TFP | CPTR_EL2_TZ; + + __activate_traps_fpsimd32(vcpu); + } + + kvm_write_cptr_el2(val); + write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt; + + isb(); + /* + * At this stage, and thanks to the above isb(), S2 is + * configured and enabled. We can now restore the guest's S1 + * configuration: SCTLR, and only then TCR. + */ + write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL1), SYS_SCTLR); + isb(); + write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR); + } +} + +static void __deactivate_traps(struct kvm_vcpu *vcpu) +{ + extern char __kvm_hyp_host_vector[]; + + ___deactivate_traps(vcpu); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + u64 val; + + /* + * Set the TCR and SCTLR registers in the exact opposite + * sequence as __activate_traps (first prevent walks, + * then force the MMU on). A generous sprinkling of isb() + * ensure that things happen in this exact order. + */ + val = read_sysreg_el1(SYS_TCR); + write_sysreg_el1(val | TCR_EPD1_MASK | TCR_EPD0_MASK, SYS_TCR); + isb(); + val = read_sysreg_el1(SYS_SCTLR); + write_sysreg_el1(val | SCTLR_ELx_M, SYS_SCTLR); + isb(); + } + + __deactivate_traps_common(vcpu); + + write_sysreg(this_cpu_ptr(&kvm_init_params)->hcr_el2, hcr_el2); + + kvm_reset_cptr_el2(vcpu); + write_sysreg(__kvm_hyp_host_vector, vbar_el2); +} + +/* Save VGICv3 state on non-VHE systems */ +static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu) +{ + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { + __vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3); + __vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3); + } +} + +/* Restore VGICv3 state on non-VHE systems */ +static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu) +{ + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { + __vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3); + __vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3); + } +} + +/* + * Disable host events, enable guest events + */ +#ifdef CONFIG_HW_PERF_EVENTS +static bool __pmu_switch_to_guest(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu_events *pmu = &vcpu->arch.pmu.events; + + if (pmu->events_host) + write_sysreg(pmu->events_host, pmcntenclr_el0); + + if (pmu->events_guest) + write_sysreg(pmu->events_guest, pmcntenset_el0); + + return (pmu->events_host || pmu->events_guest); +} + +/* + * Disable guest events, enable host events + */ +static void __pmu_switch_to_host(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu_events *pmu = &vcpu->arch.pmu.events; + + if (pmu->events_guest) + write_sysreg(pmu->events_guest, pmcntenclr_el0); + + if (pmu->events_host) + write_sysreg(pmu->events_host, pmcntenset_el0); +} +#else +#define __pmu_switch_to_guest(v) ({ false; }) +#define __pmu_switch_to_host(v) do {} while (0) +#endif + +/* + * Handler for protected VM MSR, MRS or System instruction execution in AArch64. + * + * Returns true if the hypervisor has handled the exit, and control should go + * back to the guest, or false if it hasn't. + */ +static bool kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + /* + * Make sure we handle the exit for workarounds and ptrauth + * before the pKVM handling, as the latter could decide to + * UNDEF. + */ + return (kvm_hyp_handle_sysreg(vcpu, exit_code) || + kvm_handle_pvm_sysreg(vcpu, exit_code)); +} + +static const exit_handler_fn hyp_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, + [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg, + [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, + [ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops, +}; + +static const exit_handler_fn pvm_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, + [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, + [ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops, +}; + +static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) +{ + if (unlikely(kvm_vm_is_protected(kern_hyp_va(vcpu->kvm)))) + return pvm_exit_handlers; + + return hyp_exit_handlers; +} + +/* + * Some guests (e.g., protected VMs) are not be allowed to run in AArch32. + * The ARMv8 architecture does not give the hypervisor a mechanism to prevent a + * guest from dropping to AArch32 EL0 if implemented by the CPU. If the + * hypervisor spots a guest in such a state ensure it is handled, and don't + * trust the host to spot or fix it. The check below is based on the one in + * kvm_arch_vcpu_ioctl_run(). + * + * Returns false if the guest ran in AArch32 when it shouldn't have, and + * thus should exit to the host, or true if a the guest run loop can continue. + */ +static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + struct kvm *kvm = kern_hyp_va(vcpu->kvm); + + if (kvm_vm_is_protected(kvm) && vcpu_mode_is_32bit(vcpu)) { + /* + * As we have caught the guest red-handed, decide that it isn't + * fit for purpose anymore by making the vcpu invalid. The VMM + * can try and fix it by re-initializing the vcpu with + * KVM_ARM_VCPU_INIT, however, this is likely not possible for + * protected VMs. + */ + vcpu_clear_flag(vcpu, VCPU_INITIALIZED); + *exit_code &= BIT(ARM_EXIT_WITH_SERROR_BIT); + *exit_code |= ARM_EXCEPTION_IL; + } +} + +/* Switch to the guest for legacy non-VHE systems */ +int __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + struct kvm_s2_mmu *mmu; + bool pmu_switch_needed; + u64 exit_code; + + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + */ + if (system_uses_irq_prio_masking()) { + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); + pmr_sync(); + } + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + pmu_switch_needed = __pmu_switch_to_guest(vcpu); + + __sysreg_save_state_nvhe(host_ctxt); + /* + * We must flush and disable the SPE buffer for nVHE, as + * the translation regime(EL1&0) is going to be loaded with + * that of the guest. And we must do this before we change the + * translation regime to EL2 (via MDCR_EL2_E2PB == 0) and + * before we load guest Stage1. + */ + __debug_save_host_buffers_nvhe(vcpu); + + /* + * We're about to restore some new MMU state. Make sure + * ongoing page-table walks that have started before we + * trapped to EL2 have completed. This also synchronises the + * above disabling of SPE and TRBE. + * + * See DDI0487I.a D8.1.5 "Out-of-context translation regimes", + * rule R_LFHQG and subsequent information statements. + */ + dsb(nsh); + + __kvm_adjust_pc(vcpu); + + /* + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + * + * Also, and in order to be able to deal with erratum #1319537 (A57) + * and #1319367 (A72), we must ensure that all VM-related sysreg are + * restored before we enable S2 translation. + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_state_nvhe(guest_ctxt); + + mmu = kern_hyp_va(vcpu->arch.hw_mmu); + __load_stage2(mmu, kern_hyp_va(mmu->arch)); + __activate_traps(vcpu); + + __hyp_vgic_restore_state(vcpu); + __timer_enable_traps(vcpu); + + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + + __sysreg_save_state_nvhe(guest_ctxt); + __sysreg32_save_state(vcpu); + __timer_disable_traps(vcpu); + __hyp_vgic_save_state(vcpu); + + /* + * Same thing as before the guest run: we're about to switch + * the MMU context, so let's make sure we don't have any + * ongoing EL1&0 translations. + */ + dsb(nsh); + + __deactivate_traps(vcpu); + __load_host_stage2(); + + __sysreg_restore_state_nvhe(host_ctxt); + + if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) + __fpsimd_save_fpexc32(vcpu); + + __debug_switch_to_host(vcpu); + /* + * This must come after restoring the host sysregs, since a non-VHE + * system may enable SPE here and make use of the TTBRs. + */ + __debug_restore_host_buffers_nvhe(vcpu); + + if (pmu_switch_needed) + __pmu_switch_to_host(vcpu); + + /* Returning to host will clear PSR.I, remask PMR if needed */ + if (system_uses_irq_prio_masking()) + gic_write_pmr(GIC_PRIO_IRQOFF); + + host_ctxt->__hyp_running_vcpu = NULL; + + return exit_code; +} + +asmlinkage void __noreturn hyp_panic(void) +{ + u64 spsr = read_sysreg_el2(SYS_SPSR); + u64 elr = read_sysreg_el2(SYS_ELR); + u64 par = read_sysreg_par(); + struct kvm_cpu_context *host_ctxt; + struct kvm_vcpu *vcpu; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + vcpu = host_ctxt->__hyp_running_vcpu; + + if (vcpu) { + __timer_disable_traps(vcpu); + __deactivate_traps(vcpu); + __load_host_stage2(); + __sysreg_restore_state_nvhe(host_ctxt); + } + + /* Prepare to dump kvm nvhe hyp stacktrace */ + kvm_nvhe_prepare_backtrace((unsigned long)__builtin_frame_address(0), + _THIS_IP_); + + __hyp_do_panic(host_ctxt, spsr, elr, par); + unreachable(); +} + +asmlinkage void __noreturn hyp_panic_bad_stack(void) +{ + hyp_panic(); +} + +asmlinkage void kvm_unexpected_el2_exception(void) +{ + __kvm_unexpected_el2_exception(); +} diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c new file mode 100644 index 000000000000..edd969a1f36b --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -0,0 +1,516 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#include <linux/irqchip/arm-gic-v3.h> + +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> + +#include <hyp/adjust_pc.h> + +#include <nvhe/fixed_config.h> + +#include "../../sys_regs.h" + +/* + * Copies of the host's CPU features registers holding sanitized values at hyp. + */ +u64 id_aa64pfr0_el1_sys_val; +u64 id_aa64pfr1_el1_sys_val; +u64 id_aa64isar0_el1_sys_val; +u64 id_aa64isar1_el1_sys_val; +u64 id_aa64isar2_el1_sys_val; +u64 id_aa64mmfr0_el1_sys_val; +u64 id_aa64mmfr1_el1_sys_val; +u64 id_aa64mmfr2_el1_sys_val; +u64 id_aa64smfr0_el1_sys_val; + +/* + * Inject an unknown/undefined exception to an AArch64 guest while most of its + * sysregs are live. + */ +static void inject_undef64(struct kvm_vcpu *vcpu) +{ + u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); + + *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR); + *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); + + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); + + __kvm_adjust_pc(vcpu); + + write_sysreg_el1(esr, SYS_ESR); + write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR); + write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR); + write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR); +} + +/* + * Returns the restricted features values of the feature register based on the + * limitations in restrict_fields. + * A feature id field value of 0b0000 does not impose any restrictions. + * Note: Use only for unsigned feature field values. + */ +static u64 get_restricted_features_unsigned(u64 sys_reg_val, + u64 restrict_fields) +{ + u64 value = 0UL; + u64 mask = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0); + + /* + * According to the Arm Architecture Reference Manual, feature fields + * use increasing values to indicate increases in functionality. + * Iterate over the restricted feature fields and calculate the minimum + * unsigned value between the one supported by the system, and what the + * value is being restricted to. + */ + while (sys_reg_val && restrict_fields) { + value |= min(sys_reg_val & mask, restrict_fields & mask); + sys_reg_val &= ~mask; + restrict_fields &= ~mask; + mask <<= ARM64_FEATURE_FIELD_BITS; + } + + return value; +} + +/* + * Functions that return the value of feature id registers for protected VMs + * based on allowed features, system features, and KVM support. + */ + +static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) +{ + u64 set_mask = 0; + u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; + + set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); + + return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask; +} + +static u64 get_pvm_id_aa64pfr1(const struct kvm_vcpu *vcpu) +{ + const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm); + u64 allow_mask = PVM_ID_AA64PFR1_ALLOW; + + if (!kvm_has_mte(kvm)) + allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE); + + return id_aa64pfr1_el1_sys_val & allow_mask; +} + +static u64 get_pvm_id_aa64zfr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for Scalable Vectors, therefore, hyp has no sanitized + * copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64ZFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64dfr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for debug, including breakpoints, and watchpoints, + * therefore, pKVM has no sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64DFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64dfr1(const struct kvm_vcpu *vcpu) +{ + /* + * No support for debug, therefore, hyp has no sanitized copy of the + * feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64DFR1_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64afr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for implementation defined features, therefore, hyp has no + * sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64AFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64afr1(const struct kvm_vcpu *vcpu) +{ + /* + * No support for implementation defined features, therefore, hyp has no + * sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64AFR1_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64isar0(const struct kvm_vcpu *vcpu) +{ + return id_aa64isar0_el1_sys_val & PVM_ID_AA64ISAR0_ALLOW; +} + +static u64 get_pvm_id_aa64isar1(const struct kvm_vcpu *vcpu) +{ + u64 allow_mask = PVM_ID_AA64ISAR1_ALLOW; + + if (!vcpu_has_ptrauth(vcpu)) + allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_APA) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_API) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPA) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPI)); + + return id_aa64isar1_el1_sys_val & allow_mask; +} + +static u64 get_pvm_id_aa64isar2(const struct kvm_vcpu *vcpu) +{ + u64 allow_mask = PVM_ID_AA64ISAR2_ALLOW; + + if (!vcpu_has_ptrauth(vcpu)) + allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_APA3) | + ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_GPA3)); + + return id_aa64isar2_el1_sys_val & allow_mask; +} + +static u64 get_pvm_id_aa64mmfr0(const struct kvm_vcpu *vcpu) +{ + u64 set_mask; + + set_mask = get_restricted_features_unsigned(id_aa64mmfr0_el1_sys_val, + PVM_ID_AA64MMFR0_RESTRICT_UNSIGNED); + + return (id_aa64mmfr0_el1_sys_val & PVM_ID_AA64MMFR0_ALLOW) | set_mask; +} + +static u64 get_pvm_id_aa64mmfr1(const struct kvm_vcpu *vcpu) +{ + return id_aa64mmfr1_el1_sys_val & PVM_ID_AA64MMFR1_ALLOW; +} + +static u64 get_pvm_id_aa64mmfr2(const struct kvm_vcpu *vcpu) +{ + return id_aa64mmfr2_el1_sys_val & PVM_ID_AA64MMFR2_ALLOW; +} + +/* Read a sanitized cpufeature ID register by its encoding */ +u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id) +{ + switch (id) { + case SYS_ID_AA64PFR0_EL1: + return get_pvm_id_aa64pfr0(vcpu); + case SYS_ID_AA64PFR1_EL1: + return get_pvm_id_aa64pfr1(vcpu); + case SYS_ID_AA64ZFR0_EL1: + return get_pvm_id_aa64zfr0(vcpu); + case SYS_ID_AA64DFR0_EL1: + return get_pvm_id_aa64dfr0(vcpu); + case SYS_ID_AA64DFR1_EL1: + return get_pvm_id_aa64dfr1(vcpu); + case SYS_ID_AA64AFR0_EL1: + return get_pvm_id_aa64afr0(vcpu); + case SYS_ID_AA64AFR1_EL1: + return get_pvm_id_aa64afr1(vcpu); + case SYS_ID_AA64ISAR0_EL1: + return get_pvm_id_aa64isar0(vcpu); + case SYS_ID_AA64ISAR1_EL1: + return get_pvm_id_aa64isar1(vcpu); + case SYS_ID_AA64ISAR2_EL1: + return get_pvm_id_aa64isar2(vcpu); + case SYS_ID_AA64MMFR0_EL1: + return get_pvm_id_aa64mmfr0(vcpu); + case SYS_ID_AA64MMFR1_EL1: + return get_pvm_id_aa64mmfr1(vcpu); + case SYS_ID_AA64MMFR2_EL1: + return get_pvm_id_aa64mmfr2(vcpu); + default: + /* Unhandled ID register, RAZ */ + return 0; + } +} + +static u64 read_id_reg(const struct kvm_vcpu *vcpu, + struct sys_reg_desc const *r) +{ + return pvm_read_id_reg(vcpu, reg_to_encoding(r)); +} + +/* Handler to RAZ/WI sysregs */ +static bool pvm_access_raz_wi(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (!p->is_write) + p->regval = 0; + + return true; +} + +/* + * Accessor for AArch32 feature id registers. + * + * The value of these registers is "unknown" according to the spec if AArch32 + * isn't supported. + */ +static bool pvm_access_id_aarch32(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) { + inject_undef64(vcpu); + return false; + } + + /* + * No support for AArch32 guests, therefore, pKVM has no sanitized copy + * of AArch32 feature id registers. + */ + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL1), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) > ID_AA64PFR0_EL1_ELx_64BIT_ONLY); + + return pvm_access_raz_wi(vcpu, p, r); +} + +/* + * Accessor for AArch64 feature id registers. + * + * If access is allowed, set the regval to the protected VM's view of the + * register and return true. + * Otherwise, inject an undefined exception and return false. + */ +static bool pvm_access_id_aarch64(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) { + inject_undef64(vcpu); + return false; + } + + p->regval = read_id_reg(vcpu, r); + return true; +} + +static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + /* pVMs only support GICv3. 'nuf said. */ + if (!p->is_write) + p->regval = ICC_SRE_EL1_DIB | ICC_SRE_EL1_DFB | ICC_SRE_EL1_SRE; + + return true; +} + +/* Mark the specified system register as an AArch32 feature id register. */ +#define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 } + +/* Mark the specified system register as an AArch64 feature id register. */ +#define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 } + +/* + * sys_reg_desc initialiser for architecturally unallocated cpufeature ID + * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2 + * (1 <= crm < 8, 0 <= Op2 < 8). + */ +#define ID_UNALLOCATED(crm, op2) { \ + Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \ + .access = pvm_access_id_aarch64, \ +} + +/* Mark the specified system register as Read-As-Zero/Write-Ignored */ +#define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi } + +/* Mark the specified system register as not being handled in hyp. */ +#define HOST_HANDLED(REG) { SYS_DESC(REG), .access = NULL } + +/* + * Architected system registers. + * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 + * + * NOTE: Anything not explicitly listed here is *restricted by default*, i.e., + * it will lead to injecting an exception into the guest. + */ +static const struct sys_reg_desc pvm_sys_reg_descs[] = { + /* Cache maintenance by set/way operations are restricted. */ + + /* Debug and Trace Registers are restricted. */ + + /* AArch64 mappings of the AArch32 ID registers */ + /* CRm=1 */ + AARCH32(SYS_ID_PFR0_EL1), + AARCH32(SYS_ID_PFR1_EL1), + AARCH32(SYS_ID_DFR0_EL1), + AARCH32(SYS_ID_AFR0_EL1), + AARCH32(SYS_ID_MMFR0_EL1), + AARCH32(SYS_ID_MMFR1_EL1), + AARCH32(SYS_ID_MMFR2_EL1), + AARCH32(SYS_ID_MMFR3_EL1), + + /* CRm=2 */ + AARCH32(SYS_ID_ISAR0_EL1), + AARCH32(SYS_ID_ISAR1_EL1), + AARCH32(SYS_ID_ISAR2_EL1), + AARCH32(SYS_ID_ISAR3_EL1), + AARCH32(SYS_ID_ISAR4_EL1), + AARCH32(SYS_ID_ISAR5_EL1), + AARCH32(SYS_ID_MMFR4_EL1), + AARCH32(SYS_ID_ISAR6_EL1), + + /* CRm=3 */ + AARCH32(SYS_MVFR0_EL1), + AARCH32(SYS_MVFR1_EL1), + AARCH32(SYS_MVFR2_EL1), + ID_UNALLOCATED(3,3), + AARCH32(SYS_ID_PFR2_EL1), + AARCH32(SYS_ID_DFR1_EL1), + AARCH32(SYS_ID_MMFR5_EL1), + ID_UNALLOCATED(3,7), + + /* AArch64 ID registers */ + /* CRm=4 */ + AARCH64(SYS_ID_AA64PFR0_EL1), + AARCH64(SYS_ID_AA64PFR1_EL1), + ID_UNALLOCATED(4,2), + ID_UNALLOCATED(4,3), + AARCH64(SYS_ID_AA64ZFR0_EL1), + ID_UNALLOCATED(4,5), + ID_UNALLOCATED(4,6), + ID_UNALLOCATED(4,7), + AARCH64(SYS_ID_AA64DFR0_EL1), + AARCH64(SYS_ID_AA64DFR1_EL1), + ID_UNALLOCATED(5,2), + ID_UNALLOCATED(5,3), + AARCH64(SYS_ID_AA64AFR0_EL1), + AARCH64(SYS_ID_AA64AFR1_EL1), + ID_UNALLOCATED(5,6), + ID_UNALLOCATED(5,7), + AARCH64(SYS_ID_AA64ISAR0_EL1), + AARCH64(SYS_ID_AA64ISAR1_EL1), + AARCH64(SYS_ID_AA64ISAR2_EL1), + ID_UNALLOCATED(6,3), + ID_UNALLOCATED(6,4), + ID_UNALLOCATED(6,5), + ID_UNALLOCATED(6,6), + ID_UNALLOCATED(6,7), + AARCH64(SYS_ID_AA64MMFR0_EL1), + AARCH64(SYS_ID_AA64MMFR1_EL1), + AARCH64(SYS_ID_AA64MMFR2_EL1), + ID_UNALLOCATED(7,3), + ID_UNALLOCATED(7,4), + ID_UNALLOCATED(7,5), + ID_UNALLOCATED(7,6), + ID_UNALLOCATED(7,7), + + /* Scalable Vector Registers are restricted. */ + + RAZ_WI(SYS_ERRIDR_EL1), + RAZ_WI(SYS_ERRSELR_EL1), + RAZ_WI(SYS_ERXFR_EL1), + RAZ_WI(SYS_ERXCTLR_EL1), + RAZ_WI(SYS_ERXSTATUS_EL1), + RAZ_WI(SYS_ERXADDR_EL1), + RAZ_WI(SYS_ERXMISC0_EL1), + RAZ_WI(SYS_ERXMISC1_EL1), + + /* Performance Monitoring Registers are restricted. */ + + /* Limited Ordering Regions Registers are restricted. */ + + HOST_HANDLED(SYS_ICC_SGI1R_EL1), + HOST_HANDLED(SYS_ICC_ASGI1R_EL1), + HOST_HANDLED(SYS_ICC_SGI0R_EL1), + { SYS_DESC(SYS_ICC_SRE_EL1), .access = pvm_gic_read_sre, }, + + HOST_HANDLED(SYS_CCSIDR_EL1), + HOST_HANDLED(SYS_CLIDR_EL1), + HOST_HANDLED(SYS_CSSELR_EL1), + HOST_HANDLED(SYS_CTR_EL0), + + /* Performance Monitoring Registers are restricted. */ + + /* Activity Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_CNTP_TVAL_EL0), + HOST_HANDLED(SYS_CNTP_CTL_EL0), + HOST_HANDLED(SYS_CNTP_CVAL_EL0), + + /* Performance Monitoring Registers are restricted. */ +}; + +/* + * Checks that the sysreg table is unique and in-order. + * + * Returns 0 if the table is consistent, or 1 otherwise. + */ +int kvm_check_pvm_sysreg_table(void) +{ + unsigned int i; + + for (i = 1; i < ARRAY_SIZE(pvm_sys_reg_descs); i++) { + if (cmp_sys_reg(&pvm_sys_reg_descs[i-1], &pvm_sys_reg_descs[i]) >= 0) + return 1; + } + + return 0; +} + +/* + * Handler for protected VM MSR, MRS or System instruction execution. + * + * Returns true if the hypervisor has handled the exit, and control should go + * back to the guest, or false if it hasn't, to be handled by the host. + */ +bool kvm_handle_pvm_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + const struct sys_reg_desc *r; + struct sys_reg_params params; + unsigned long esr = kvm_vcpu_get_esr(vcpu); + int Rt = kvm_vcpu_sys_get_rt(vcpu); + + params = esr_sys64_to_params(esr); + params.regval = vcpu_get_reg(vcpu, Rt); + + r = find_reg(¶ms, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs)); + + /* Undefined (RESTRICTED). */ + if (r == NULL) { + inject_undef64(vcpu); + return true; + } + + /* Handled by the host (HOST_HANDLED) */ + if (r->access == NULL) + return false; + + /* Handled by hyp: skip instruction if instructed to do so. */ + if (r->access(vcpu, ¶ms, r)) + __kvm_skip_instr(vcpu); + + if (!params.is_write) + vcpu_set_reg(vcpu, Rt, params.regval); + + return true; +} + +/* + * Handler for protected VM restricted exceptions. + * + * Inject an undefined exception into the guest and return true to indicate that + * the hypervisor has handled the exit, and control should go back to the guest. + */ +bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + inject_undef64(vcpu); + return true; +} diff --git a/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c new file mode 100644 index 000000000000..29305022bc04 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/sysreg-sr.h> + +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> + +/* + * Non-VHE: Both host and guest must save everything. + */ + +void __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_save_el1_state(ctxt); + __sysreg_save_common_state(ctxt); + __sysreg_save_user_state(ctxt); + __sysreg_save_el2_return_state(ctxt); +} + +void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_restore_el1_state(ctxt); + __sysreg_restore_common_state(ctxt); + __sysreg_restore_user_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); +} diff --git a/arch/arm64/kvm/hyp/nvhe/timer-sr.c b/arch/arm64/kvm/hyp/nvhe/timer-sr.c new file mode 100644 index 000000000000..3aaab20ae5b4 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/timer-sr.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <clocksource/arm_arch_timer.h> +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +void __kvm_timer_set_cntvoff(u64 cntvoff) +{ + write_sysreg(cntvoff, cntvoff_el2); +} + +/* + * Should only be called on non-VHE or hVHE setups. + * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe(). + */ +void __timer_disable_traps(struct kvm_vcpu *vcpu) +{ + u64 val, shift = 0; + + if (has_hvhe()) + shift = 10; + + /* Allow physical timer/counter access for the host */ + val = read_sysreg(cnthctl_el2); + val |= (CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN) << shift; + write_sysreg(val, cnthctl_el2); +} + +/* + * Should only be called on non-VHE or hVHE setups. + * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe(). + */ +void __timer_enable_traps(struct kvm_vcpu *vcpu) +{ + u64 clr = 0, set = 0; + + /* + * Disallow physical timer access for the guest + * Physical counter access is allowed if no offset is enforced + * or running protected (we don't offset anything in this case). + */ + clr = CNTHCTL_EL1PCEN; + if (is_protected_kvm_enabled() || + !kern_hyp_va(vcpu->kvm)->arch.timer_data.poffset) + set |= CNTHCTL_EL1PCTEN; + else + clr |= CNTHCTL_EL1PCTEN; + + if (has_hvhe()) { + clr <<= 10; + set <<= 10; + } + + sysreg_clear_set(cnthctl_el2, clr, set); +} diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c new file mode 100644 index 000000000000..a60fb13e2192 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/tlb.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/tlbflush.h> + +#include <nvhe/mem_protect.h> + +struct tlb_inv_context { + u64 tcr; +}; + +static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu, + struct tlb_inv_context *cxt, + bool nsh) +{ + /* + * We have two requirements: + * + * - ensure that the page table updates are visible to all + * CPUs, for which a dsb(DOMAIN-st) is what we need, DOMAIN + * being either ish or nsh, depending on the invalidation + * type. + * + * - complete any speculative page table walk started before + * we trapped to EL2 so that we can mess with the MM + * registers out of context, for which dsb(nsh) is enough + * + * The composition of these two barriers is a dsb(DOMAIN), and + * the 'nsh' parameter tracks the distinction between + * Inner-Shareable and Non-Shareable, as specified by the + * callers. + */ + if (nsh) + dsb(nsh); + else + dsb(ish); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + u64 val; + + /* + * For CPUs that are affected by ARM 1319367, we need to + * avoid a host Stage-1 walk while we have the guest's + * VMID set in the VTTBR in order to invalidate TLBs. + * We're guaranteed that the S1 MMU is enabled, so we can + * simply set the EPD bits to avoid any further TLB fill. + */ + val = cxt->tcr = read_sysreg_el1(SYS_TCR); + val |= TCR_EPD1_MASK | TCR_EPD0_MASK; + write_sysreg_el1(val, SYS_TCR); + isb(); + } + + /* + * __load_stage2() includes an ISB only when the AT + * workaround is applied. Take care of the opposite condition, + * ensuring that we always have an ISB, but not two ISBs back + * to back. + */ + __load_stage2(mmu, kern_hyp_va(mmu->arch)); + asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT)); +} + +static void __tlb_switch_to_host(struct tlb_inv_context *cxt) +{ + __load_host_stage2(); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + /* Ensure write of the host VMID */ + isb(); + /* Restore the host's TCR_EL1 */ + write_sysreg_el1(cxt->tcr, SYS_TCR); + } +} + +void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, int level) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt, false); + + /* + * We could do so much better if we had the VA as well. + * Instead, we invalidate Stage-2 for this IPA, and the + * whole of Stage-1. Weep... + */ + ipa >>= 12; + __tlbi_level(ipas2e1is, ipa, level); + + /* + * We have to ensure completion of the invalidation at Stage-2, + * since a table walk on another CPU could refill a TLB with a + * complete (S1 + S2) walk based on the old Stage-2 mapping if + * the Stage-1 invalidation happened first. + */ + dsb(ish); + __tlbi(vmalle1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, int level) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt, true); + + /* + * We could do so much better if we had the VA as well. + * Instead, we invalidate Stage-2 for this IPA, and the + * whole of Stage-1. Weep... + */ + ipa >>= 12; + __tlbi_level(ipas2e1, ipa, level); + + /* + * We have to ensure completion of the invalidation at Stage-2, + * since a table walk on another CPU could refill a TLB with a + * complete (S1 + S2) walk based on the old Stage-2 mapping if + * the Stage-1 invalidation happened first. + */ + dsb(nsh); + __tlbi(vmalle1); + dsb(nsh); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu, + phys_addr_t start, unsigned long pages) +{ + struct tlb_inv_context cxt; + unsigned long stride; + + /* + * Since the range of addresses may not be mapped at + * the same level, assume the worst case as PAGE_SIZE + */ + stride = PAGE_SIZE; + start = round_down(start, stride); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt, false); + + __flush_s2_tlb_range_op(ipas2e1is, start, pages, stride, 0); + + dsb(ish); + __tlbi(vmalle1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt, false); + + __tlbi(vmalls12e1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt, false); + + __tlbi(vmalle1); + asm volatile("ic iallu"); + dsb(nsh); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_vm_context(void) +{ + /* Same remark as in __tlb_switch_to_guest() */ + dsb(ish); + __tlbi(alle1is); + dsb(ish); +} |